Hypothesis Testing: One population z-test for µ when σ is known.
How does the average hair length of a University of Maryland student today compare to the US average 20 years ago of 2.7 inches? You sample 40 students and get a sample average of 3.7 inches. Somehow you know the population standard deviation for U of MD student hair lengths is 0.5 inches. Are hair lengths longer today than 20 years ago?
a. What question is being asked – ID the population and be sure to include a direction of interest if one exists.
b. State your null and alternative hypotheses. If you use symbols (not required) be sure to define the symbol and give statements in terms of population inference.
c. Set up the equation to analyze these data. Solve to a z* value.
d. Assume the critical value is 1.96 for a 2 tailed (or nondirectional) test and 1.65 for a 1 tailed (or directional) test. The value could be positive or negative depending on your question and hypotheses. What conclusion do you make about the null hypothesis?
e. Provide a statement of conclusion that includes the 3 pieces of statistical evidence and makes inference back to the population

Answers

Answer 1

We can conclude with 95% confidence that the average hair length of University of Maryland students today is significantly longer than the US average 20 years ago.

a. The question being asked is whether the average hair length of University of Maryland students today is longer than the US average 20 years ago, with a direction of interest being "longer than".

b. Null hypothesis: The average hair length of University of Maryland students today is not significantly different from the US average 20 years ago (µ = 2.7 inches).

Alternative hypothesis: The average hair length of University of Maryland students today is significantly greater than the US average 20 years ago (µ > 2.7 inches).

Symbolically, H0: µ = 2.7 and Ha: µ > 2.7

c. The equation to analyze these data is: z = (x - µ) / (σ / √n), where x is the sample mean (3.7 inches), µ is the hypothesized population mean (2.7 inches), σ is the population standard deviation (0.5 inches), and n is the sample size (40).

Substituting the values, we get:

z = (3.7 - 2.7) / (0.5 / √40) = 4.47

d. The calculated z-value of 4.47 is much greater than the critical value of 1.96 for a two-tailed test or 1.65 for a one-tailed test at the 5% significance level. Therefore, we reject the null hypothesis and conclude that the average hair length of University of Maryland students today is significantly greater than the US average 20 years ago.

e. Based on the calculated z-value, the rejection of the null hypothesis, and the chosen level of significance, we can conclude with 95% confidence that the average hair length of University of Maryland students today is significantly longer than the US average 20 years ago.

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Related Questions

3. Isaac paid $119. 70 for a racket, a bag and a pair of shoes. A pair of shoes cost three times as much as a bag. The racket cost twice as much as the bag. How much did Isaac pay for the racket?​

Answers

Isaac pay for the cost of racket is 39.9.

The cost of a pair of shoes is three times the cost of a bag, so we can write:

Cost of shoes = 3b

Similarly, the cost of the racket is twice the cost of the bag, so we can write:

Cost of racket = 2b

Now we can use the given information to set up an equation:

Cost of racket + Cost of bag + Cost of shoes = $119.70

Substituting the expressions we found above, we get:

2b + b + 3b = $119.70

Simplifying the equation:

6b = $119.70

Dividing both sides by 6:

b = $19.95

So the cost of the bag is $19.95.

We can use this to find the costs of the shoes and racket:

Cost of shoes = 3b = 3($19.95) = $59.85

Cost of racket = 2b = 2($19.95) = $39.90

Therefore, Isaac paid $39.90 for the racket.

A cost is an expenditure required to produce or sell a product or get an asset ready for normal use. In other words, it's the amount paid to manufacture a product, purchase inventory, sell merchandise, or get equipment ready to use in a business process.

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The capital structure for the Carion Corporation is provided here. The company plans to maintain its debt structure in the future. If the firm has a 5.5 percent of debt, a 13.5 percent cost of preferred stock and an 18 percent cost of common stock, what is the firm's weighted average cost of capital?
CAPITAL STRUCTURE in thousand$
Bonds.............................$1,083
Preferred Stock................$268
Common Stock................$3,681
Total...............................$5032

Answers

The firm's weighted average cost of capital is 15.074%

To calculate the weighted average cost of capital (WACC), we need to follow these steps:

1. Determine the weight of each component of the capital structure (debt, preferred stock, and common stock) by dividing the value of each component by the total capital.
2. Multiply the weight of each component by its respective cost.
3. Sum the weighted costs to obtain the WACC.

Here's the step-by-step calculation:

1. Calculate the weights:
Debt weight = $1,083 / $5,032 = 0.215
Preferred stock weight = $268 / $5,032 = 0.053
Common stock weight = $3,681 / $5,032 = 0.732

2. Calculate the weighted costs:
Weighted cost of debt = 0.215 x 5.5% = 0.011825
Weighted cost of preferred stock = 0.053 x 13.5% = 0.007155
Weighted cost of common stock = 0.732 x 18% = 0.13176

3. Sum the weighted costs to find the WACC:
WACC = 0.011825 + 0.007155 + 0.13176 = 0.15074 or 15.074%

Therefore, we can state that the firm's weighted average cost of capital is 15.074%.

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what is true about the points (-1, 6) and (-1, -6) when graphed on a coordinate plane?

Answers

The points lie on a vertical line passing through the point x = -1.

We have,

The two points (-1, 6) and (-1, -6) have the same x-coordinate but different y-coordinates.

This means that they lie on a vertical line passing through the point x = -1.

When graphed on a coordinate plane, the line would appear as a vertical line at x = -1, with one point above the x-axis and the other point below the x-axis.

Thus,

The points lie on a vertical line passing through the point x = -1.

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Which of the following problem types can always be solved using the law of sines? Check all that apply.

Answers

Answer:

A, C, E

Step-by-step explanation:

remember to law of sine :

a/sin(A) = b/sin(B) = c/sin(C)

or the "upside-down" version :

sin(A)/a = sin(B)/b = sin(C)/c

with a, b, c being the sides of the triangle, and A, B, C being the corresponding opposite angles in the triangle.

so, as you can clearly see, we always need at least one angle and one side (in fact either 2 angles one side or 1 angle 2 sides) to use the law of sine to solve the rest of the triangle.

therefore, the answer options A, C, E are correct.

for SSS (all 3 sides are known) we need the law of cosine to solve the angles (at least one of them, and then we could continue with either law).

remember :

c² = a² + b² - 2ab×cos(C)

again, a,b,c are the sides, and C is the opposite angle of whatever side we define as "c".

that's why I always call this the extended Pythagoras.

for AAA (all 3 angles are known) we cannot solve the triangle, because dilated triangles all have the same angles. and therefore there are infinitely many triangles with the same angles.

Answer this question Use the Second Derivative Midpoint Formula formula to approximate f'(0.6) for the table data points given that h = 0.06.
Select the correct answer
A. 2376.342000000
B. 594.085500000
C. 2079.299250000
D. 1782.256500000
E. 297.042750000

Answers

To approximate f'(0.6) using the Second Derivative Midpoint Formula with the given table data points and h = 0.06, follow these steps:

1. Identify the relevant data points: f(0.54), f(0.6), and f(0.66).
2. Apply the Second Derivative Midpoint Formula: f'(0.6) ≈ (f(0.66) - 2f(0.6) + f(0.54)) / (h^2).

Unfortunately, I cannot provide a specific answer without the values for f(0.54), f(0.6), and f(0.66).

Please provide these values, and I will gladly help you complete the calculation.

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Question 2: The set cover problem is defined as follows:
SETCOVER = {(B, S1, S2, Sm, K): B is a finite set; m is an integer; S1, S2, Sm are sets with US = B; K is an integer; there exists a subset IC (1.2...., m} of size K, such that UierS₁ = B}.
Prove that the language SETCOVER is in NP.

Answers

Answer:

14

Step-by-step explanation:

eere4

If a given certificate C is a legitimate answer to the instance, we can check in polynomial time if it is (B, S1, S2, ..., Sm, K) of SETCOVER. Hence, the language SETCOVER is in NP.

To prove that the language SETCOVER is in NP, we need to show that given an instance (B, S1, S2, ..., Sm, K) of SETCOVER and a certificate C, we can verify in polynomial time whether C is a valid solution to the instance.

The certificate C in this case is a subset IC of {1, 2, ..., m} of size K, which represents the indices of the sets that form a cover for B. To verify whether C is a valid solution, we need to check two things:

Verify that IC has size K: We can simply count the number of elements in IC and check if it equals K. This can be done in O(m) time, which is polynomial in the size of the input.

Verify that the sets S_i for i in IC form a cover for B: We can iterate through the elements in B and check whether each element is present in at least one of the sets S_i, where i is in IC. Since B has at most |B| elements, and each set S_i has at most |B| elements, this can be done in O(K |B|) time, which is polynomial in the size of the input.

Therefore, If a given certificate C is a legitimate answer to the instance, we can check in polynomial time if it is (B, S1, S2, ..., Sm, K) of SETCOVER. Hence, the language SETCOVER is in NP.

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Use the Direct Comparison Test to determine the convergence or divergence of the s 00 Inn n + 1 n=2 In n 1 x X n+1 converges diverges 8. [0. 5/1 Points] DETAILS PREVIOUS ANSWERS LARCALCET7 9. 4. 26. Use the Limit Comparison Test to determine the convergence or divergence of the series. Σ (4) sin() sin n=1 n lim = L > 0 - I converges o diverges

Answers

By the Comparison Test, we can conclude that Σ (4sin(n))/([tex]n^2[/tex] - 1) converges.

We can use the Limit Comparison Test to determine the convergence or divergence of the series:

∑(4 sin(n))/n

To do this, we need to find a series whose convergence is known and which can be compared to the given series. Let's choose the series ∑(1/n) since we know that it diverges.

We take the limit of the ratio of the nth term of each series as n approaches infinity:

lim n→∞ (4 sin(n)/n)/(1/n) = lim n→∞ 4 sin(n) = DNE

Since the limit does not exist, we cannot apply the Limit Comparison Test. Therefore, Therefore, by the Comparison Test, we can conclude that Σ (4sin(n))/([tex]n^2[/tex] - 1) converges.

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Credit card limits are included in a. M1 but not M2 b. M2 but not M1 c. M1 and M2 d. Neither M1 nor M2.

Answers

Credit card limits are included in M2 but not M1. The correct answer is b.

M1 and M2 are measures of the money supply that are used by economists and policymakers to analyze the state of the economy and make monetary policy decisions.

M1 includes the most liquid forms of money, such as physical currency, traveler's checks, demand deposits, and other checkable deposits. M2 includes all of the components of M1, as well as less liquid forms of money, such as savings accounts, money market accounts, and time deposits.

Credit card limits are not included in M1, as they do not represent actual money or funds that are available for immediate spending. Credit cards represent a line of credit, which is a promise by the credit card issuer to lend money to the cardholder up to a certain limit. As such, credit card limits are not considered part of the money supply, and are not included in M1.

However, credit card limits are included in M2, as they represent a potential source of funds that can be used for spending or saving. Even though credit card limits are not immediately available as cash or funds that can be spent, they can be used to obtain loans or other forms of credit that can be used to make purchases or investments.

As such, credit card limits are considered part of the broader definition of the money supply that is included in M2. The correct answer is b.

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Can someone please help me
If the volume of the hemisphere of the lime below is 6 cm3, what is the volume of the whole lime?

Volume of lime = ___ cm3

Answers

The volume of the whole lime represented by a sphere is given by  12 cubic centimeters.

Volume of the lime in hemispherical shape is equal to

= 6 cubic centimeters

Let us consider 'r' be the radius of the sphere.

Volume of hemisphere = ( 2/3 ) πr³

Volume of a sphere = ( 4 /3) πr³

Relation between volume of hemisphere and volume of a whole lime sphere

Volume of a whole lime sphere = 2 times of volume of hemisphere

⇒Volume of a whole lime sphere =  2 × 6

⇒Volume of a whole lime sphere =  12 cubic centimeters.

Therefore, the volume of the whole lime is equal to  12 cubic centimeters.

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a committee of 5 members is to be selected from 6 seniors and 4 juniors. fine the number of ways in which this can be done if the committee has at least 1 junior.
a.252
b.6
c.246
d.120

Answers

A or b is the correct answer
Final answer:

The answer to the question is 'c. 246'. This is calculated by determining the total number of ways to form the committee, subtracting the ways in which only seniors can be selected to ensure at least one junior is included.

Explanation:

This question is related to combinatorics, a branch of Mathematics that deals with counting, arrangement, and permutation. Given we have 6 seniors and 4 juniors, and we need to select a committee of 5 members with at least one junior, we can approach it in the following way:

First we consider the total number of ways to form a 5-member committee without any restriction. From 10 people (6 seniors + 4 juniors), we can choose 5 in 10C5 ways, which equals 252. Next, we consider the number of ways to form a 5-member committee with only seniors. From 6 seniors, we can choose 5 in 6C5 ways, which equals 6. We subtract the number of committees that contain only seniors from the total number of committees to find the number of committees with at least one junior. Hence, 252 - 6 = 246 ways.

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Consider H0 : μ = 72 versus H1 : μ > 72 ∶ A random sample of 16 observations taken from this population produced a sample mean of 75.2. The population is normally distributed with σ = 6.
a. Calculate the p-value.
b. Considering the p-value of part a, would you reject the null hypothesis if the test were made at a significance level of .01?
c. Find the critical value and compare it with the test statistic. What would the conclusion be at a significance level of .01?

Answers

At a significance level of 0.01, the conclusion would be that there is not enough evidence to support the alternative hypothesis (H1: μ > 72).

To lea

a. To calculate the p-value, we can use the standard normal distribution and the test statistic formula:

Test statistic (Z) = (sample mean - population mean) / (population standard deviation / sqrt(sample size))

Z = (75.2 - 72) / (6 / sqrt(16))

Z = 3.2 / 1.5

Z = 2.13 (rounded to two decimal places)

To find the p-value, we need to calculate the area under the standard normal curve to the right of the test statistic (Z = 2.13). Using a standard normal distribution table or a calculator, we find that the area to the right of Z = 2.13 is approximately 0.016.

Since this is a one-sided test (H1: μ > 72), the p-value is the probability of observing a test statistic as extreme or more extreme than the one obtained. Therefore, the p-value is 0.016.

b. If the test were made at a significance level of 0.01 (1%), we would compare the p-value to the significance level. In this case, the p-value (0.016) is less than the significance level (0.01). Therefore, we would reject the null hypothesis.

c. To find the critical value at a significance level of 0.01, we need to determine the z-score that corresponds to an area of 0.01 in the upper tail of the standard normal distribution.

Using a standard normal distribution table or a calculator, we find that the critical value for a significance level of 0.01 is approximately 2.33.

Comparing the critical value (2.33) with the test statistic (Z = 2.13), we see that the test statistic is less than the critical value. In hypothesis testing, if the test statistic is less than the critical value, we fail to reject the null hypothesis.

Therefore, at a significance level of 0.01, the conclusion would be that there is not enough evidence to support the alternative hypothesis (H1: μ > 72).

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Solve for x in the equation by factoring and using the zero product property.

Answers

The solution is, the solutions using the Zero Product Property: is x =0 and 3/4.

The expression to be solved is:

4x² - 3x = 0

we know that,

The zero product property states that the solution to this equation is the values of each term equals to 0.

now, we have,

4x² - 3x = 0

or, x ( 4x - 3 ) = 0

i.e. we get,

x × ( 4x - 3 ) = 0

so, using the Zero Product Property:

we get,

x = 0

or,

( 4x - 3 ) = 0

so, we have,

x = 0 or, x = 3/4

The answers are 0 and 3/4.

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A.2 A paper reported on a study to test if tires on city buses in a particular city were filled to the appropriate pressure which was determined to be 70psi. Based on a sample of n = 20 bus tires, the paper reported a sample mean of x = 62psi and a two-tailed test p-value of 0.043. Let μ be the true mean tire pressure for the population of tires on city buses in this city. Which of the following is a valid conclusion from the test using a significance level of 5%? A: There is evidence that μ < 70. B: There is evidence that μ = 70. C: There is evidence that μ ≠ 70. D: The probability that μ = 70 is 0.043. E: There is not enough evidence to conclude that u ≠ 70.

Answers

Option E is incorrect because we have enough evidence to reject the null hypothesis.

The correct answer is (C) There is evidence that μ ≠ 70.

The null hypothesis is that the true mean tire pressure for the population of tires on city buses in this city is equal to 70psi, i.e., H0: μ = 70. The alternative hypothesis is that it is not equal to 70psi, i.e., Ha: μ ≠ 70.

The p-value of 0.043 is less than the significance level of 0.05. Therefore, we reject the null hypothesis and conclude that there is evidence that the true mean tire pressure is not equal to 70psi.

Option A is incorrect because we cannot conclude that the true mean tire pressure is less than 70psi. Option B is incorrect because we cannot conclude that the true mean tire pressure is equal to 70psi. Option D is incorrect because the p-value is not the probability that μ = 70. Option E is incorrect because we have enough evidence to reject the null hypothesis.

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Two professors at a nearby university want to co-author a new textbook in either economics or statistics. They feel that if they write an economics book, they have a 50 percent chance of placing it with a major publisher, and it should ultimately sell about 40,000 copies. If they can't get a major publisher to take it, then they feel they have an 80 percent chance of placing it with a smaller publisher, with ultimate sales of 30,000 copies. On the other hand, if they write a statistics book, they feel they have a 40 percent chance of placing it with a major publisher, and it should result in ultimate sales of about 50,000 copies. If they can't get a major publisher to take it, they feel they have a 50 percent chance of placing it with a smaller publisher, with ultimate sales of 35,000 copies.
a. Create a decision tree diagram
b. What is the probability that the economics book would wind up being placed with a smaller publisher?
c. What is the probability that the statistics book would wind up being placed with a smaller publisher?
d. What is the expected value for the decision alternative to write the economics book?
e. What is the expected value for the decision alternative to write the statistics book?
f. What is the expected value for the optimum decision alternative?

Answers

The decision with the highest expected value should be chosen. In this case, the economics book has a higher expected value (32,000 copies) compared to the statistics book (30,500 copies). Therefore, the optimum decision alternative is to write the economics book.


a. Decision tree diagram:
2. Branch off two nodes from the root for each option.
3. From the economics book node, branch off two nodes for major and smaller publisher placement. Assign probabilities of 50% and 50% for each.
4. From the statistics book node, branch off two nodes for major and smaller publisher placement. Assign probabilities of 40% and 60% for each.
5. Assign ultimate sales to each end node (40,000 and 30,000 for economics; 50,000 and 35,000 for statistics).

b. The probability that the economics book would wind up being placed with a smaller publisher is 50% (1 - 50% chance of placing it with a major publisher).

c. The probability that the statistics book would wind up being placed with a smaller publisher is 60% (1 - 40% chance of placing it with a major publisher).

d. Expected value for the decision alternative to write the economics book:
(0.50 * 40,000) + (0.50 * 0.80 * 30,000) = 20,000 + 12,000 = 32,000 copies.

e. Expected value for the decision alternative to write the statistics book:
(0.40 * 50,000) + (0.60 * 0.50 * 35,000) = 20,000 + 10,500 = 30,500 copies.

f. Expected value for the optimum decision alternative:
The decision with the highest expected value should be chosen. In this case, the economics book has a higher expected value (32,000 copies) compared to the statistics book (30,500 copies). Therefore, the optimum decision alternative is to write the economics book.

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Suppose y=f(x) is continuous for all real numbers. Use the sign chart for the first derivative to answer the question that follows: f'() 0 +++ 0 1 Determine which of the following best describes what must be true about absolute extrema on the interval [0,00) There is an absolute maximum at x-1 There is an absolute minimum at x--1 There is an absolute maximum at x=-1 There is an absolute minimum at x 1

Answers

Based on the provided information, f'(x) changes from positive to negative at x=1, indicating that the function has a local maximum at this point.

Since y=f(x) is continuous for all real numbers and the interval is [0, ∞), there is an absolute maximum at x=1. The best description of the absolute extrema is: "There is an absolute maximum at x=1." Based on the sign chart for the first derivative, we know that the function is increasing from negative infinity to x=-1, and then decreasing from x=-1 to positive infinity. This means that there is an absolute maximum at x=-1 since the function is increasing to that point and decreasing after it. Therefore, the correct statement is: "There is an absolute maximum at x=-1."

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Let u=r and v= and use cylindrical coordinates to parametrize the surface.Set up the double integral to find the surface area

Answers

To find the surface area of the given surface using cylindrical coordinates, first we need to find the parametrization of the surface. Since you have not provided the explicit form of the surface, I'll provide you with a general procedure.

Let's consider a surface S given by the equation G(r, θ, z) = 0, where r and θ are cylindrical coordinates.

1. Parametrize the surface:
To parametrize the surface, express it in terms of two parameters (say, r and θ). Then, a parametrization of the surface can be given as:

R(r, θ) = (r*cos(θ), r*sin(θ), z(r, θ))

2. Compute the partial derivatives:
Now, compute the partial derivatives of R with respect to r and θ:

R_r = (∂R/∂r) = (cos(θ), sin(θ), ∂z/∂r)
R_θ = (∂R/∂θ) = (-r*sin(θ), r*cos(θ), ∂z/∂θ)

3. Cross product and magnitude:
Calculate the cross product of these partial derivatives and find its magnitude:

N = R_r × R_θ = (a, b, c)
|M| = sqrt(a^2 + b^2 + c^2)

4. Set up the double integral:
Finally, set up the double integral to find the surface area of S:

Surface Area = ∬_D |M| dr dθ

Here, D is the domain of the parameters r and θ on the surface. To evaluate the integral, you will need to know the specific form of the surface and the limits of integration for r and θ.

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3. Patricia needs to have $30,000 for her daughter's college tuition that is due in exactly 2 years. How much
should Patricia invest in an account paying 6% interest, compounded semi-annually, so that she will have the
necessary funds?

$23,098.42
$25, 437.92
$26, 654.70
$24,398.10

Answers

If Patricia needs to have $30,000 for her daughter's college tuition that is due in exactly 2 years, she should invest C. $26, 654.70 (present value) in an account paying 6% interest compounded semi-annually.

How the present value is computed:

The present value describes the current investment needed to earn a future value.

The present value can be determined using the PV formula or an online finance calculator.

N (# of periods) = 4 semi-annual periods (2 years x 2)

I/Y (Interest per year) = 6%

PMT (Periodic Payment) = $0

FV (Future Value) = $30,000

Results:

Present Value (PV) = $26,654.70

Total Interest = $3,345.30

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Triangle ABC has the following known dimensions.
Angle A = 107°
Angle C = 42°
Side a = 25 inches
What is the length of side c?
A. 25 inches
B. 18.3 inches
C. 16 inches
D. 17.5 inches

Answers

Answer: Side C = 17.5

Step-by-step explanation: We have to follow the laws of sines. So we would do 25sin(42)/sin(107).

Or sin(42) x 25

Then divide that value by sin(107).

Betty the Baker is baking cakes. Each cake uses 112 cups of flour. She has a 50 pound bag of flour which equals 181 12 cups. How many cakes can she bake with 50 pounds of flour? Write an equation to solve the problem. Be prepared to explain how you determined your answer.

Answers

The equation to show the number of cakes that can be baked with 50 pounds of flour, is 181. 5 = c × 112.

How to find the number of cakes ?

If we represent the quantity of cakes Betty can make as "c", and it is known that each cake requires 112 cups of flour, with a total of 181.5 cups available, then the equation may be expressed as:

Total flour = Number of cakes × Flour per cake

181. 5 = c × 112

c = 181. 5 / 112

c = 1.62 cakes

In conclusion, 1. 62 cakes can be baked.

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Do you dislike waiting in line? A supermarket chain used computer simulation and information technology to reduce the average waiting time for customers at 2,300 stores. Using a new
system, which allows the supermarket to better predict when shoppers will be checking out, the company was able to decrease average customer waiting time to just 19 seconds.
(a) Assume that supermarket waiting times are exponentially distributed. Show the probability density function of waiting time at the supermarket.
f(x)=(1/B)e -(x/B). x≥0
(1/19)e. -(x/19) elsewhere
(b) What is the probability that a customer will have to wait between 15 and 30 seconds? (Round your answer to four decimal places.)
0 2462
(c) What is the probability that a customer will have to wait more than 2 minutes? (Round your answer to four decimal places.)
0.0099

Answers

The probability that a customer will have to wait more than 2 minutes is 0.0099.

(a) Since the waiting time at the supermarket is assumed to be exponentially distributed, the probability density function is given by:

f(x) = (1/B)e^(-(x/B)) for x ≥ 0

= 0 elsewhere

where B is the mean waiting time. In this case, the mean waiting time is 19 seconds. Therefore, the probability density function of waiting time at the supermarket is:

f(x) = (1/19)e^(-(x/19)) for x ≥ 0

= 0 elsewhere

(b) To find the probability that a customer will have to wait between 15 and 30 seconds, we need to find the area under the probability density function between x=15 and x=30. This can be calculated using the cumulative distribution function (CDF) of the exponential distribution:

P(15 ≤ x ≤ 30) = ∫15^30 f(x)dx = ∫15^30 (1/19)e^(-(x/19)) dx

Using integration by substitution, let u = -(x/19), then du/dx = -1/19 and dx = -19 du:

P(15 ≤ x ≤ 30) = ∫-(15/19)^-(30/19) e^udu = e^(-(15/19)) - e^(-(30/19))

P(15 ≤ x ≤ 30) ≈ 0.2462 (rounded to four decimal places).

Therefore, the probability that a customer will have to wait between 15 and 30 seconds is 0.2462.

(c) To find the probability that a customer will have to wait more than 2 minutes, we need to find the area under the probability density function for x > 120 seconds (2 minutes). This can be calculated using the CDF of the exponential distribution:

P(x > 120) = ∫120^∞ f(x)dx = ∫120^∞ (1/19)e^(-(x/19)) dx

Using integration by substitution, let u = -(x/19), then du/dx = -1/19 and dx = -19 du:

P(x > 120) = ∫-(120/19)^-∞ e^udu = e^(-(120/19))

P(x > 120) ≈ 0.0099 (rounded to four decimal places).

Therefore, the probability that a customer will have to wait more than 2 minutes is 0.0099.

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The accompanying table shows the number of bacteria present in a certain culture over a 5 hour period, where x is the time, in hours, and y is the number of bacteria. Write an exponential regression equation for this set of data, rounding all coefficients to the nearest hundredth. Using this equation, determine the number of bacteria present after 16 hours, to the nearest whole number. Type here to search Hours (x) Bacteria (y) 0 940 1 1034 2 1105 1223 1352 1520 3 4 5 (+) McAfee​

Answers

The exponential regression equation for the set of data is given as follows: y = 931.61(1.1)^x.

The number of bacteria after 16 hours is given as follows:

4,281 bacteria.

How to define an exponential function?

An exponential function has the definition presented as follows:

y = ab^x.

In which the parameters are given as follows:

a is the value of y when x = 0.b is the rate of change.

For exponential regression, we must insert the points of a data-set into an exponential regression calculator.

The points for this problem are given as follows:

(0, 940), (1, 1034), (2, 1105), (3, 1223), (4, 1352), (5, 1520).

Inserting these points into a calculator, the equation is given as follows:

y = 931.61(1.1)^x.

The number of bacteria after 16 hours is given as follows:

y = 931.61 x (1.1)^16

y = 4,281 bacteria.

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A trampoline park has a trampoline that is 8 yards wide and 12 yards long. Approximate the distance (in yards) between opposite con
nearest tenth.

Answers

The distance between the opposite sides of the trampoline can be found to be 14. 42 yards

How to find the distance ?

To find the distance between the opposite sides of the trampoline, we are essentially finding the diagonal length. We can use the Pythagorean theorem to do this by dividing the trampoline into two right triangles.

The distance between the opposite sides would then be:

c ² = a ² + b ²

c ² = 8 ² + 12 ²

c ² = 64 + 144

c ² = 208

c = √ 208

c = 14. 42 yards

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When operating normally, a manufacturing process produces tablets for which the mean weight of the active ingredient is 5 grams, and the standard deviation is 0.025 gram. For a random sample of 12 tables the following weights of active ingredient (in grams) were found:
5.01 4.69 5.03 4.98 4.98 4.95 5.00 5.00 5.03 5.01 5.04 4.95
Without assuming that the population variance is known, test the null hypothesis that the population mean weight of active ingredient per tablet is 5 grams. Use a two-sided alternative and a 5% significance level. State any assumptions that you make.
State the following:
1. The null and alternate hypothesis statements
2. The significance level
3. The test statistic
4. Decision Rules
5. Calculate Test Statistic and find the p-value
6. Interpret the results of the test.
7. Assumptions

Answers

The p-value for a two-tailed test is 0.0769.

The null hypothesis (H0) is that the population mean weight of active ingredient per tablet is 5 grams. The alternative hypothesis (Ha) is that the population mean weight of active ingredient per tablet is not equal to 5 grams.

H0: µ = 5

Ha: µ ≠ 5

The significance level is 5%.

The test statistic is t = (x - µ) / (s / √n), where x is the sample mean, µ is the hypothesized population mean, s is the sample standard deviation, and n is the sample size.

The decision rules: Reject H0 if |t| > tα/2,n-1, where tα/2,n-1 is the t-value from the t-distribution with n-1 degrees of freedom and α/2 level of significance.

Calculating the test statistic and p-value:

x = (5.01 + 4.69 + 5.03 + 4.98 + 4.98 + 4.95 + 5.00 + 5.00 + 5.03 + 5.01 + 5.04 + 4.95) / 12 = 4.9983

s = sqrt([(5.01 - 4.9983)² + (4.69 - 4.9983)² + ... + (4.95 - 4.9983)²] / 11) = 0.0383

t = (4.9983 - 5) / (0.0383 / sqrt(12)) = -1.931

Degrees of freedom = n-1 = 11

At α = 0.05, t0.025,11 = 2.201

The p-value for a two-tailed test is P(|t| > 1.931) = 0.0769.

Interpretation: Since the p-value (0.0769) is greater than the significance level (0.05), we fail to reject the null hypothesis. There is not enough evidence to conclude that the population mean weight of active ingredient per tablet is different from 5 grams at the 5% level of significance.

Assumptions: We assume that the sample is randomly selected and comes from a normally distributed population. We also assume that the sample standard deviation is a good estimate of the population standard deviation.

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You intend to estimate a population mean ji with the following sample. 60.3 65.2 60 70.6 62 55.9 You believe the population is normally distributed. Find the 95% confidence interval. Enter your answer as an open-interval ... parentheses) accurate to two decimal places (because the sample data are reported accurate to one decimal place), 95% C.I. =

Answers

The 95% confidence interval for the population mean is (54.70, 70.96).

To find the 95% confidence interval for the population mean, we need to first find the sample mean and sample standard deviation.

Sample Mean (x) = (60.3 + 65.2 + 60 + 70.6 + 62 + 55.9) / 6 = 62.33

Sample Standard Deviation (s) = sqrt([(60.3 - 62.33)^2 + (65.2 - 62.33)^2 + (60 - 62.33)^2 + (70.6 - 62.33)^2 + (62 - 62.33)^2 + (55.9 - 62.33)^2] / (6 - 1)) = 5.28

Next, we can use the formula for the confidence interval:

CI = x ± t*(s/sqrt(n))

where x is the sample mean, s is the sample standard deviation, n is the sample size, and t is the t-value for the 95% confidence level with (n-1) degrees of freedom.

From a t-distribution table with 5 degrees of freedom (n-1 = 6-1 = 5) and a 95% confidence level, we find that the t-value is 2.571.

Plugging in the values, we get:

CI = 62.33 ± 2.571*(5.28/sqrt(6))

CI = (54.70, 70.96)

Therefore, the 95% confidence interval for the population mean is (54.70, 70.96).

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A line graph titled Car Mileage for a Hybrid Car has number of gallons on the x-axis, and number of miles on the y-axis. 1 Gallon is 60 miles, 2 gallons is 120 miles, 3 gallons is 180 miles, and 4 gallons is 240 miles.
What is the value of y when the value of x is 1?

Answers

The value of y when the value of x is 1, can be found to be 60 miles.

How to find the value of y?

As depicted in the graph, an augmented consumption of gallons of fuel by the hybrid vehicle concomitantly correlates to an increase in mileage capacity.

Concretely, according to our research data, we confirm that for every gallon expended, there is a mileage expansion rate of 60 units. Hence, when the quantity x equals 1, it implies usage of one gallon only.

Accordingly, empirical evidence suggests that traveling precisely sixty miles remains possible on utilization of one gallon which thus confirms the efficiency of using hybrid cars as a viable option.

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12×67=
24×87=
88×88+45=
34+78×23=
66÷4×87=​

Answers

Answer:

1, 768

2, 2088

3, 7789

4, 1828

5, 1435.

Jane figures that her monthly car insurance payment of $170 is equal to 30% of the amount of her monthly auto loan payment. What is her total combined monthly expense for auto loan payment and insurance (rounded to the nearest dollar)?

Answers

Jane's total combined monthly cost for auto loan payment and insurance is $736.67 (rounded to the nearest dollar).

If Jane's monthly car insurance payment of $170 is same to 30% of her monthly car loan fee, then we are able to set up the subsequent equation:

0.3x = 170

Where x is the monthly auto loan fee. To solve for x, we will divide each facets by using 0.3:

x = 170 / 0.3 = $566.67

So, Jane's monthly auto loan charge is $566.67.

To discover her general combined monthly price for auto loan price and insurance, we simply upload her monthly car coverage charge to her monthly auto loan payment:

$566.67 + $170 = $736.67

Consequently, Jane's total combined monthly cost for auto loan payment and coverage is $736.67

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Evaluate the integral

Answers

The integral expression [tex]\int\limits^4_{-4} {f(x)} \, dx[/tex] when evaluated has a value of 352/3

Evaluating the integral expression

From the question, we have the following parameters that can be used in our computation:

[tex]\int\limits^4_{-4} {f(x)} \, dx[/tex]

The function f(x) is a piecewise function

When the functions are combined, we have

f(x) = 4 + 16 - x²

Evaluate the like terms

So, we have

f(x) = 20 - x²

So, we have

[tex]\int\limits^4_{-4} {f(x)} \, dx = \int\limits^4_{-4} {20 - x\²} \, dx[/tex]

Integrate the function

So, we have

[tex]\int\limits^4_{-4} {f(x)} \, dx = 20x - \frac{x^3}3|\limits^4_{-4}[/tex]

Expand the integral expression

This gives

[tex]\int\limits^4_{-4} {f(x)} \, dx = 20(4) - \frac{4^3}3 - 20(-4) + \frac{(-4)^3}3[/tex]

Evaluate the expression

So, we have

[tex]\int\limits^4_{-4} {f(x)} \, dx = \frac{352}{3}[/tex]

Hence, the solution is 352/3

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The population of a city is expected to increase by
7.5
%
7.5% next year. If
p
p represents the current population, which expression represents the expected population next year?
A
1+0.0751+0.075
B
p+0.075p+0.075
C
1.075p1.075p
D
1.75p1.75p

Answers

If p represents the current population, the expression that represents the expected population next year is C. [tex]1.075p[/tex].

Which expression represents the expected population?

To find the expected population next year, we need to add the current population to the percentage increase.

The percentage increase is 7.5% of the current population which can be expressed as 0.075p. So, expression that represents the expected population of the city next year will be:

= Current population + Percentage increase

= p + 0.075p

= 1.075p.

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In each of the following scenarios, we consider the distribution of a quantity along an axis. a. Suppose that the function c(x) = 200 + 100e0.13 models the density of traffic on a straight road, measured in cars per mile, where x is number of miles east of a major interchange, and consider the definite integral Só (200 + 100e-0.12) dr. i. What are the units on the product c(x) · Ax? ii. What are the units on the definite integral and its Riemann sum approximation given by 1 cle *= c(x) dx = c(x;)Ax? 2=1 iii. Evaluate the definite integral ſ c(x) dx = fó (200 + 100e -0.13) de and write one sentence to explain the meaning of the value you find. b. On a 6 foot long shelf filled with books, the function B models the distribution of the weight of the books, in pounds per inch, where x is the number of inches from the left end of the bookshelf. Let B(x) be given by the rule B(x) = 0.5 + (2+1)2 i. What are the units on the product B(x) · Ax? ii. What are the units on the definite integral and its Riemann sum approximation given by 36 B(x)dt = B(;)Az? 12 21 ii. Evaluate the definite integral f," B(z) dx = fo? (0.5+ (213) de + (x+1) and write one sentence to explain the meaning of the value you find.

Answers

In scenario a, the function c(x) represents the density of traffic on a straight road, measured in cars per mile, where x is the number of miles east of a major interchange. The product c(x) · Ax has units of cars, as it represents the number of cars in a certain segment of the road. The definite integral ∫ c(x) dx and its Riemann sum approximation given by 1/n ∑ c(xi) · Δx have units of cars per mile, as they represent the average density of traffic over a certain distance. When evaluating the definite integral ∫ c(x) dx, we get a value that represents the total number of cars on the road between two given points.

In scenario b, the function B(x) represents the distribution of the weight of books on a shelf, in pounds per inch, where x is the number of inches from the left end of the shelf. The product B(x) · Ax has units of pounds, as it represents the weight of books in a certain segment of the shelf. The definite integral ∫ B(x) dx and its Riemann sum approximation given by 1/n ∑ B(xi) · Δx have units of pounds, as they represent the total weight of books on the shelf. When evaluating the definite integral ∫ B(x) dx, we get a value that represents the total weight of books on the shelf.
a. i. The units on the product c(x) · Δx are cars per mile (from c(x)) multiplied by miles (from Δx), resulting in cars.

a. ii. The units on the definite integral and its Riemann sum approximation are the same as the units on the product c(x) · Δx, which are cars.

a. iii. To evaluate the definite integral, we have:

∫(200 + 100e^(-0.12x)) dx

Using the integral rules, we get:

[200x - (100/0.12)e^(-0.12x)] (evaluate this from 0 to a specific value to find the total cars between 0 and that value)

The meaning of the value is the total number of cars on the road between 0 miles and the specified value of x miles east of the major interchange.

b. i. The units on the product B(x) · Δx are pounds per inch (from B(x)) multiplied by inches (from Δx), resulting in pounds.

b. ii. The units on the definite integral and its Riemann sum approximation are the same as the units on the product B(x) · Δx, which are pounds.

b. iii. To evaluate the definite integral, we have:

∫(0.5 + (x+1)^2) dx

Using the integral rules, we get:

[0.5x + (1/3)(x+1)^3] (evaluate this from 0 to 72 to find the total weight of books on the shelf)

The meaning of the value is the total weight of the books on the 6-foot-long shelf.

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