The expression for r in terms of R is: r = (1-R²) / R²
What is square root?In mathematics, the square root of a number is a value that, when multiplied by itself, gives the original number. For example, the square root of 9 is 3, because 3 multiplied by itself gives 9:
3 x 3 = 9
The square root symbol is √, and the number under the symbol is called the radicand. So, √9 is read as "the square root of 9."
According to question:Starting with the given equation:
R = √(r-1) / √(r+1)
Let's first clear the square roots by squaring both sides:
R² = (r-1) / (r+1)
Now, let's multiply both sides by (r+1) to eliminate the denominator on the right-hand side:
R²(r+1) = r-1
Expanding the left-hand side:
R²r + R² = r-1
Subtracting R²r from both sides:
R² - R²r = -1
Factoring out R² on the left-hand side:
R²(1-r) = -1
Dividing both sides by (1-r):
R² = -1 / (1-r)
Finally, we can take the square root of both sides and multiply by -1 to isolate r:
r = -1 / R² + 1
Therefore, the expression for r in terms of R is:
r = (1-R²) / R²
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Make r the subject of the following:
R= √(r-1) / √(r+1)
PLEASE HELP <3 Kelly walks from the 1st floor to the 5th floor. Avery walks from the 8th floor to the 4th floor. Which best describes the distance Kelly and Avery walk?
Avery walks a greater distance than Kelly.
B Kelly walks a greater distance than Avery.
C Kelly walks at a slower speed than Avery.
D Kelly and Avery walk the same distance.
Answer:
D. Kelly and Avery walk the same distance.
Step-by-step explanation:
Kelly walked from the 1st floor to the 5th floor. That means she walked 4 floors.
Avery walked from the 8th floor to the 4th floor.
8 - 4 = 4.
They walked the same distance, except Avery went down, and Kelly went up, which is unrelated.
answer question please but DO NOT ROUND IT . 1 / 3*5 + 2
[tex]=\frac{1}{15} +2\\[/tex]
⇒We can only add the numbers if they have the same denominator, to do so we can first convert 2 into a fraction
[tex]=\frac{1}{15} +\frac{2(15)}{1(15)} \\=\frac{1}{15} +\frac{30}{15} \\=\frac{31}{15} \\[/tex]
the anterior cruciate ligament (acl) is one of the ligaments that help stabilize the knee. surgery is often recommended if the acl is completely torn, and recovery time from the surgery can be lengthy. a medical center developed a new surgical procedure designed to reduce the average recovery time from the surgery. to test the effectiveness of the new procedure, a study was conducted in which 210 patients needing surgery to repair a torn acl were randomly assigned to receive either the standard procedure or the new procedure. (a) based on the design of the study, would a statistical
The outcomes of the statistical analysis can give medical professionals and patients important knowledge regarding the possible advantages of the new procedure.
what is probability ?The study of random events or phenomena is the focus of the mathematical field of probability. It is a way to gauge how likely something is to happen. It is represented by a number between 0 and 1, where 0 denotes the event's impossibility and 1 denotes its certainty. There are numerous ways to calculate probabilities, including utilizing theoretical or mathematical models, empirical data, and experimental data.
given
A statistical analysis would be useful to evaluate the effectiveness of the novel technique to the standard procedure based on the study's design.
The recovery periods of the two patient groups might be compared using statistical techniques like hypothesis testing and confidence intervals to assess the efficacy of the new therapy.
Researchers can establish whether the new approach is statistically significantly superior than the usual procedure in terms of minimizing recovery time by comparing the recovery times of the two groups.
The outcomes of the statistical analysis can give medical professionals and patients important knowledge regarding the possible advantages of the new procedure.
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Landon owns 16 baseball cards, which is 4 times as many as Phillip owns. The equation 4p = 16 represents this situation where p is the number of baseball cards Phillip owns. Which number line represents the solution to the equation?
The number line :0-------------4-------------10 represents the solution to the equation.
What Is an integer?
An integer is a whole number that can be positive, negative, or zero. In other words, integers are numbers that can be written without fractions or decimals.
Examples of integers are: -3, -2, -1, 0, 1, 2, 3, and so on.
The equation 4p = 16 represents the number of baseball cards owned by Phillip, where p is the number of baseball cards owned by him.
To solve for p, we can divide both sides of the equation by 4:
4p/4 = 16/4
p = 4
Therefore, Phillip owns 4 baseball cards.
Now we need to represent this solution on a number line. We can draw a number line with 0 on the left and 10 on the right, marking every integer in between. Then we can place a dot at the point corresponding to the number 4, which represents the number of baseball cards owned by Phillip.
Therefore the number line :
0-------------4-------------10
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luis wants to create a graph using powerpoint to show how much weight he lost after starting an exercise plan over six months. which type of graph should he use?
Luis wants to create a graph using PowerPoint to show how much weight he lost after starting an exercise plan over six months. The type of graph that Luis should use is a line graph.
What is a line graph?A line graph is a method of displaying data or information on a two-dimensional Cartesian plane. It is mostly used to display changes over time or trends. It is ideal for data that has a lot of numeric data or that change frequently over time.The line graph is made up of two lines, one horizontal and the other vertical, which connect the data points in a sequential order. It is best used for visual representation of data, as it provides the viewer with a simple, visual representation of the data.
The x-axis and y-axis of a line graph represent the independent and dependent variables, respectively. The x-axis is often used to represent the time or the data being analyzed, while the y-axis represents the numerical values that are being analyzed.To create a line graph using PowerPoint, you can use the Insert Chart button to add your data, then choose Line Graph as the type of chart you want to create. You can then customize the chart as you like, including changing the colors, fonts, and background.
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hey there!! I NEED URGENT HELP!! PLEASE SHOW FULL SOLUTIONS AND ONLY ANSWER IF YOU KNOW! NO CALCULUS PLEASE! THAT WOULD BE VERY APPRECIATED!!
Answer:
depth: 5 cmwidth: 15 cmlength: 13 cmStep-by-step explanation:
You want to know the dimensions of a cuboid cereal box with volume 975 cm³ that is 3 times as wide as deep, and 2 cm shorter than wide.
VolumeLet x represent the depth of the box. Then the width is 3 times that, or 3x. The length is 2 cm less than the width, so is (3x -2). The volume is the product of these dimensions.
V = DWL
975 = x(3x)(3x -2)
SolutionWe like to graph an equation like this in the form ...
f(x) = 0
so the solution is the x-intercept of the graph of f(x). Subtracting 975 puts the equation in that form:
x(3x)(3x -2) -975 = 0
The attachment shows the graph of x(3x)(3x -2), and that it has its only real solution at x=5. This means the dimensions are ...
depth: 5 cmwidth: 15 cmlength: 13 cm__
Alternate solution
Sometimes finding the solution to a cubic isn't easy. As a starting point, we can recognize that 3x-2 is about the same as 3x, so the value of x will be approximately the solution to ...
975 = x(3x)(3x) = 9x³
x = ∛(975/9) ≈ 4.8
The nearest integer to this value is x=5, so that can be a good value to check: 5(3·5)(3·5 -2) = 5·15·13 =975. (x = 5 works!)
Iterated solution
We can rewrite the equation as ...
975 = 3x²(3x -2)
325 = x²(3x -2)
325/(3x -2) = x²
x = √(325/(3x -2))
A value of x will be a solution to this equation if it makes the right side equal to the left side. This equation works as an "iterator," meaning we can use a value of x on the right side, and the value of that function will give a value of x on the left that is closer to the solution. The table in the second attachment shows this convergence to x=5.
It isn't always easy to find a suitable iteration function for a cubic or higher degree polynomial equation. The usual tools are Descartes' Rule of Signs, and the Rational Root Theorem. The best iteration functions are found using calculus.
AP Statistics Hypothesis Testing
The average amount of rainfall in the Amazon Rainforest for a year is recorded to be normally distributed with a
mean of 200 cm. Twelve regions in the Amazon Rainforest are randomly sampled. The total yearly rainfalls, in
centimeters, for these regions were reported as follows:
188 232 210 198 202. 193. 219. 202, 252, 156, 184, 222
Do this data provide sufficient evidence that the annual rainfall in the Amazon rainforest is different than 200 cm?
Therefore, based on this collection of data during a significance level of 0.05, there is insufficient proof to draw the conclusion that the average annual precipitation in the Amazonian rain forest is less than 200 cm.
What kind of hypothesis would you use?Hypothesis The amount of pleasure increases with daily solar exposure. The presumed reason in this case and the factor that is independent is sun exposure. The expected impact, or dependent variable, is the degree of happiness.
To determine if the data provide sufficient that the annual rainfall in the Amazon rainforest is different than 200 cm, we can perform a hypothesis test with the following hypotheses:
Null hypothesis: The true mean annual rainfall in the Amazon rainforest is equal to 200 cm.
Alternative hypothesis: The true mean annual rainfall in the Amazon rainforest is different than 200 cm.
We can use a two-sided t-test with a significance level of 0.05 to test this hypothesis.
We must first determine the population mean and standard variation.
x = (188 + 232 + 210 + 198 + 202 + 193 + 219 + 202 + 252 + 156 + 184 + 222)/12 = 202.17 cm
Sample standard deviation, s = 26.770 cm
Next, we can calculate the t-statistic:
t = (x - μ) / (s / sqrt(n)) = (202.17 - 200) / (26.770 / sqrt(12)) = 0.491
Using a t-distribution table with 11 degrees of freedom (n-1), at a significance level of 0.05, we find the critical values to be ±2.201. Since the calculated t-statistic of 0.491 is within the range of -2.201 to 2.201, we fail to reject the null hypothesis.
Therefore, there is not sufficient evidence to conclude that the annual rainfall in the Amazon rainforest is different than 200 cm based on this sample data at a significance level of 0.05.
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Julian puts money into two investments on the same day. The first pays out £225 after every 4 years and the second pays out £350 after every 6 years. A) How many years must Julian wait before both of his investments pay out in the same year? b) Give one advantage of each of Julian's investments
Before both of Julian's investments make a profit in the same year, he must wait 12 years.
a) To find the year when both investments pay out in the same year, we need to find the least common multiple (LCM) of the two payout periods: 4 years and 6 years.
The prime factorization of 4 is 2², and the prime factorization of 6 is 2 x 3. The LCM of 4 and 6 is 2² x 3 = 12.
Therefore, Julian must wait 12 years before both of his investments pay out in the same year.
b) One advantage of the investment that pays out £225 after every 4 years is that it provides a steady and predictable income stream. Julian can expect to receive the same amount every 4 years, which can help him plan for future expenses.
One advantage of the investment that pays out £350 after every 6 years is that it offers a higher payout than the other investment. Julian can potentially earn more money from this investment, although it requires a longer waiting period for the payout. Overall, the two investments offer different advantages, and Julian may choose to invest in both to balance steady income with higher potential earnings.
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PLEASE HELP ME SOMEONE its due tomorrow.
The analysis of the data to obtain the best fit line equations that model the data, indicates;
5. a. Quadratic
b. y = -0.1179·x² + 2.1124·x + 4.215
c. Please find the completed chart showing the predicted values and the in the residuals in the following section.
6. a. A linear model may not be appropriate for the data in the residual plot
b. 4
c. 5
4. a. The exponential model of the function is; y = 100·e^(-0.124·t)
b. The weight after 8 weeks is about 37.1 grams
c. The sample will be 4 grams in about 26 weeks
5. a. The equation is; y = 22.703·x + 2.5733
b. The predicted y-value at x = 10 is; y = 229.60
c. The first time is about x ≈ 3.54
What is the best fit line?The best fit line is a line that is drawn through a set of data points in such a way that it minimizes the sum of squared errors of the data.
5. The best fit model can be obtained by plotting a scatter plot of the graph, which indicates that the best fit line resembles the shape of a parabola.
Therefore;
a. The best fit equation is; Quadratic
b. The best fit equation, obtained using technology is; y = -0.1179·x² + 2.1124·x + 4.215
The square of the correlation coefficient is; R² = 0.9584
The chart can be filled with the best fit equation as follows;
[tex]\begin{tabular}{ | c | c | c | c | c | }\cline{1-4}Distance (foot) & Height (foot) & Predicted Value &Residual \\ \cline{1-4}0 & 4 & 4.215 & -0.215 \\\cline{1-4}2 & 8.4 & 8.16588 & 0.23412 \\\cline{1-4}6 & 12.1 & 13.23804 & -1.13804 \\\cline{1-4}9 & 14.2 & 14.56626 & -0.36626\\\cline{1-4}12 & 13.2 & 13.77228 & -0.57228 \\\cline{1-4}13 & 10.5 & 13.03602 & -2.53602 \\\cline{1-4}15 & 9.8 & 10.8561 & -1.0561 \\\cline{1-4}\end{tabular}[/tex]
The predicted value are obtained by plugging in the x-value into the best fit equation and the residuals is the difference between the actual value and the predicted value.
6. a. A residual plot can be used to as assessment with regards to meeting the assumptions of a linear regression model.
A residual plot that is randomly scattered about zero indicates that a linear model is appropriate for the data.
The data points in the residual plot are not expressed as being randomly scattered around zero.
The pattern that exists in the residual plot indicates that the values are positive for x-values that are either low or high, and the middle x-values have a negative residuals. Therefr;
The pattern indicates that a linear regression model may not be appropriate for the datab. The number of positive residuals = 4
c. The number of negative residuals = 5
4. The general form of the exponential model of a function, y = A × e^(-k·t) can be used to find the function for the data as follows;
A = The initial amount = The value at 0 = 100
y = The amount of radioactive material at a given time t
e = Euler's number = 2.71828
The datapoints in the table indicates;
88.3 = 100 × e^(-k × 1)
k = -㏑(0.883) ≈ 0.124
The exponential model is therefore; y = 100 × e^(-0.124·t)
b. The weight of the sample after 8 weeks can be obtained by plugging in t = 8 in the exponential function for the weight of the radioactive substance as follows;
y = 100 × e^(-0.124 × 8) ≈ 37.1
The weight of the sample after 8 weeks is about 37.1 grams
c. When the sample is 4 grams we get;
y = 4
4 = 100 × e^(-0.124 × t)
e^(-0.124 × t) = 4/100 = 1/25
-0.124 × t = ln(1/25) = -ln(25)
t = ln(25)/0.124 ≈ 26
t ≈ 26 weeks
Therefore; The weight will be 4 grams after approximately 26 weeks
5. A linear regression can be performed using MS Excel to obtain the equation that models the data as follows;
y = 22.703·x + 2.5733
The square of the regression coefficient is; R² = 0.9995
a. The most appropriate equation to model the data in the table is; y = 22.703·x + 2.5733
b. The y-value when x = 10 can be predicted by plugging in x = 10 into the model equation for the data as follows;
y = 22.703 * 10 + 2.5733 ≈ 229.60
Therefore;
The predicted y-value when x is 10 is 229.60 (rounded to the nearest tenth)c. The first time the y-value is 83, can be found by setting y = 83 in the equation and solve for x as follows;
83 = 22.703·x + 2.5733
22.703·x = (83 - 2.5733)
x = (83 - 2.5733)/22.703 ≈ 3.54
Therefore, the first time the y-value is 83 is when x is approximately 3.54
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I will mark BRAINLYIST
Answer:
119% of 550
Step-by-step explanation:
add the percentages
How to do a yes because yes is yes and yes in yes s how to yes and no
There are many cylinders with a radius of 6 meters. Let h represent the height in meters and v represent the volume in cubic meters. Write an equation that represents the volume, v , as a function of the height, h
The equation that represents the volume, v, as a function of the height, h is given as: V(h) = 36πh,
where h is the height in meters and V is the volume in cubic meters.
The volume of a cylinder can be calculated using the formula V=πr²h.
Here, we have a number of cylinders with a radius of 6 meters.
Let h represent the height in meters and v represent the volume in cubic meters.
To write an equation that represents the volume, v,
as a function of the height, h,
we can substitute the value of r (radius) with 6m in the formula of the cylinder’s volume,
V = πr²h.
So we get:
V = π(6m)²h
V = 36πh
This equation tells us that the volume of any cylinder with a radius of 6 meters can be expressed as 36πh,
where h is the height of the cylinder.
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Oliver ask 20 children's how they travel to school you are other reasonOliver ask 20 children's how they travel to school here are the reason walkOliver ask 20 children's how they travel to school here are the reason what three bicycle 2 calculate the percentage of the children who travel to school by bicycle
From the given information provided, the percentage of children who travel by bicycle is 15%.
According to the given information, out of 20 children, 3 of them travel to school by bicycle. To calculate the percentage of children who travel to school by bicycle, we need to divide the number of children who travel by bicycle by the total number of children and multiply by 100.
Percentage of children who travel to school by bicycle = (Number of children who travel by bicycle / Total number of children) x 100%
= (3/20) x 100%
= 15%
Therefore, the percentage of children who travel to school by bicycle is 15%.
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What is the slope of the line parallel to the function: * y = 50 -0.5x 50 0.5 -0.5 02
The slope of the line parallel to the function: y = 50 - 0.5x include the following: C. -0.5.
What are parallel lines?In Mathematics and Geometry, parallel lines simply refers to two (2) lines that are always the same or equal distance apart and never meet.
Generally speaking, two (2) lines are considered as parallel under the following standard conditions:
Slope, m₁ = Slope, m₂.
From the function, we have:
y = 50 - 0.5x
Slope, m = -0.5
In this context, we can reasonably infer and logically deduce that the slope of the two lines would be equal and the same:
Slope of line 1 = Slope of line 2
-0.5 = -0.5
In conclusion, we can logically deduce that the slope of the given line is equal to -0.5.
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each page number of a 488-page book is printed one time in the book. the first page is page 1 and the last page is page 488. when printing all of the page numbers, how many more 4's are printed than 8's?
the number of more 4's printed than 8's is 188 - 59 = 129.
We can approach this problem by counting the number of times the digit 4 appears and the number of times the digit 8 appears in the page numbers from 1 to 488.
First, let's count the number of times the digit 4 appears. We can break down the counting into three cases:
The digit 4 appears in the units place (page numbers 4, 14, 24, ..., 484): there are 49 such page numbers (from 4 to 484, incrementing by 10).
The digit 4 appears in the tens place (page numbers 40 to 49, 140 to 149, ..., 440 to 449): there are 50 such page numbers.
The digit 4 appears in the hundreds place (page numbers 400 to 488): there are 89 such page numbers.
Thus, the total number of times the digit 4 appears is 49 + 50 + 89 = 188.
Next, let's count the number of times the digit 8 appears. We can break down the counting into two cases:
The digit 8 appears in the tens place (page numbers 80 to 89, 180 to 189, ..., 480 to 489): there are 50 such page numbers.
The digit 8 appears in the hundreds place (page numbers 800 to 880): there are 9 such page numbers.
Thus, the total number of times the digit 8 appears is 50 + 9 = 59.
Therefore, the number of more 4's printed than 8's is 188 - 59 = 129.
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A certain computer can perform a maximum number of operations per second. If this computer is running at 40%
of the maximum and is performing 30 operations per second, what is the maximum number of operations the
computer can perform per second? Round your answer to the nearest whole number.
1. 70 operations per second
2. 12 operations per second
3. 1,200 operations per second
4. 75 operations per second
Answer:
Step-by-step explanation:
Let's represent the maximum number of operations per second as "x".
If the computer is running at 40% of the maximum, it is performing 0.4x operations per second.
We are given that the computer is performing 30 operations per second, so we can set up an equation:
0.4x = 30
Solving for x:
x = 75
Therefore, the maximum number of operations the computer can perform per second is 75.
So, the correct answer is 4. 75 operations per second.
the university of montana ski team has eight entrants in a men's downhill ski event. the coach would like the first, second, and third places to go to the team members. in how many ways can the eight team entrants achieve first, second, and third places?
There are 336 ways for the 8 team entrants to achieve the desired outcome of first, second, and third place positions.
The problem involves selecting 3 individuals out of 8 to fill the 1st, 2nd, and 3rd place positions. Since the order in which the individuals are selected matters, we need to use the permutation formula to determine the total number of ways to achieve the desired outcome.
The formula for permutation is:
P(n,r) = n! / (n-r)!
Where n is the total number of individuals, and r is the number of positions to be filled.
In this case, we need to select 3 individuals out of 8 to fill the 1st, 2nd, and 3rd place positions. Using the permutation formula, we get:
P(8,3) = 8! / (8-3)!
= 8! / 5!
= (8 x 7 x 6 x 5 x 4 x 3 x 2 x 1) / (5 x 4 x 3 x 2 x 1)
= 8 x 7 x 6
= 336
In other words, the coach has 336 possible ways to select three team members for the podium, assuming all team members have an equal chance of winning.
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A spinner is divided into five colored sections that are not of equal size: red, blue,
green, yellow, and purple. The spinner is spun several times, and the results are
recorded below:
Spinner Results
Color Frequency
Red
Blue
Green
Yellow
Purple
14
6
12
4
16
Based on these results, express the probability that the next spin will land on purple
as a fraction in simplest form.
Answer:
4/13
Step-by-step explanation:
total = 14 + 6 + 12 + 4 + 16 = 52
purple = 16
p(purple) = 16/52 = 4/13
housing costs: a government report on housing costs says that single-family home prices nationwide are skewed to the right, with a mean of $235,700. a. we collect price data from a random sample of 50 homes in orange county, california. why is it okay to use these data for inference even though the population is skewed?
It is fine to use these data because the price sample is random so bias will not interfere with the results.
Why is it okay to use this data?Based on the information, we can infer that it is correct to use the data from this sample because it is random, that is, it does not have a defined order. Therefore, it is not necessary to take bias into account because it will not have any influence on the results.
In accordance with the above, it would be incorrect to take the data from a non-random sample because information would be prioritizing and this would cause the results to be blinded.
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student id numbers are created using the digits 0-9. how many five- digit student id numbers can be created if repeat digits are allowed? what if repeats are not allowed?
There are 100,000 possible five-digit student ID numbers that can be created if repeat digits are allowed (10^5).
However, if repeats are not allowed, there are only 9 x 9 x 9 x 9 x 9 = 590,490 possible student ID numbers that can be created (9^5).
The reason for the difference is that when repeats are allowed, you can use the same digit multiple times, for example "11111".
When repeats are not allowed, you can only use each digit once, for example "12345". The possible permutations of the digits 0-9 increase as more digits are added to the ID number, meaning that the more digits there are, the more possible combinations there are.
Therefore, when repeats are not allowed, the number of possible combinations is reduced significantly. In the case of five-digit student ID numbers, the difference is almost twofold.
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midazolam 9 mg im now is ordered. the nurse has the following vial of midazolam. how many milliliters will the nurse administer? enter only the numeral (not the unit of measurement) in your answer.
1.8 ml (milliliters) the nurse will administer the vial of the Midazolam of ordered 9mg.
The formula of calculating this is D/H × Q = x
where x = Desired dose amount, D = ordered Dose amount, H = amount on hand and Q = quantity.
From the following questions we have.
9mg = order dose, 5mg = amount on hand and 1ml quantity.
x = 9/5 × 1
= 1.8 ml.
Midazolam is administered carefully .it is used for sedation and anesthesia before surgical procedure. Midazolam is a short acting drug under benzodiazepines which have sedation power, so use or administered carefully before surgical procedure.
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Activity 2 Synthesis
1. Precious says you can estimate the area of a circle by calculating 32. What do you think
each part of her expression means?
2. Do you agree with Precious? Use your earlier work to help support your thinking.
Phillip left his house and bicycled down a trail at a rate of 12 kilometers per hour. He planned to ride his bicycle to the end of the trail, which is 28 kilometers long, and then return to his house. Christine started from Phillip’s house 20 minutes later and caught up to Phillip just as he reached the end of the trail. How fast was Christine traveling?
Answer: 14.0kph
Step-by-step explanation:
a counseling service records the number of calls to their hotline for the last year. what is the forecast for august if the forecast for june was 164 and the service uses exponential smoothing with an alpha of 0.7?
Forecast for August with an alpha of 0.7 and forecast of June 164 are to be calculated using exponential smoothing.
Exponential smoothing is a forecasting method that uses a weighted average of past time-series values to forecast future values. In a time-series, data values are obtained over time, such as over months or years, and then plotted in sequence.
The weights decrease exponentially as the observations get older. The EWMA formula used in exponential smoothing is as follows:
St=α × Yt-1+(1-α) × St-1
where,St is the smoothed statistic for the current period tYt is the original observation for the current period tSt-1 is the smoothed statistic for the previous period t-1α is the smoothing parameter 0≤α≤1, and usually close to 0.1.The smoothed statistic is also called the exponentially weighted moving average (EWMA).Calculating the forecast for August with alpha=0.7 and forecast of June 164 as follows:
St=α × Yt-1+(1-α) × St-1St =0.7 × 164+(1-0.7) × 164St=164
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if you are dealt 4 cards from a standard deck of 52 cards, what is the probability that you will get 3 black cards?
The probability of getting 3 black cards out of 4 drawn from a standard deck of 52 cards is approximately 0.253 or 25.3%.
To determine the probability of getting 3 black cards out of 4 cards drawn from a standard deck of 52 cards, we can use the hypergeometric distribution.
There are 26 black cards in the deck, and the total number of ways to choose 4 cards from 52 is given by the binomial coefficient C(52, 4). The number of ways to choose 3 black cards out of 26 is given by the binomial coefficient C(26, 3).
The number of ways to choose the fourth card from the remaining 26 non-black cards is given by the binomial coefficient C(26, 1).
Therefore, the probability of getting 3 black cards out of 4 is:
P(3 black cards) = C(26, 3) * C(26, 1) / C(52, 4)
P(3 black cards) = (2600 * 26) / 270725
P(3 black cards) ≈ 0.253
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how many batteries n should be in the package in order for the probability to exceed 1%? give the smallest number n which works.
a) The probability that a battery does not reach the milestone in its first 8 hours of usage is 0.014 or 1.4%. b) The probability of this goal being met is 0.002 or 0.2%. c) The smallest value of n that satisfies P(X >= 10) > 0.01 is n = 13.
(a) To calculate the probability that a battery does not reach the milestone in its first 8 hours of usage, we need to calculate the area under the normal curve to the right of 8 hours. We can use the standard normal distribution to do this by first standardizing the value of 8 hours using the formula:
z = (x - mu) / sigma
where x is the value of 8 hours, mu is the mean of the distribution (7.36 hours), and sigma is the standard deviation (0.29 hours). Substituting these values, we get:
z = (8 - 7.36) / 0.29 = 2.21
Using a standard normal table or a calculator, we can find that the area to the right of z = 2.21 is approximately 0.014.
(b) We want to find the probability that at least 10 batteries out of a pack of 12 last until 7.5 hours of usage. This is a binomial distribution with n = 12 and p = the probability that a single battery lasts until 7.5 hours.
To find p, we can use the standard normal distribution again by standardizing the value of 7.5 hours:
z = (7.5 - 7.36) / 0.29 = 0.48
Using a standard normal table or a calculator, we can find that the area to the right of z = 0.48 is approximately 0.316. Therefore, the probability that a single battery lasts until 7.5 hours is 0.316.
Now we can use the binomial distribution formula to calculate the probability that at least 10 batteries out of 12 last until 7.5 hours:
P(X >= 10) = 1 - P(X < 10)
where X is the number of batteries that last until 7.5 hours, and P(X < 10) is the cumulative probability of 9 or fewer batteries lasting until 7.5 hours. Using a binomial calculator or a standard normal table, we can find that:
P(X < 10) = 0.998
Therefore, P(X >= 10) = 1 - 0.998 = 0.002 or 0.2%.
(c) We want to find the smallest value of n such that the probability of at least 10 batteries out of n lasting until 7.5 hours is greater than 1%. This is equivalent to finding the smallest n such that:
P(X >= 10) > 0.01
Using a binomial calculator or a standard normal table, we can find that:
P(X < 10) = 0.989 when n = 10
P(X < 10) = 0.970 when n = 11
P(X < 10) = 0.942 when n = 12
Therefore, the smallest value of n that satisfies P(X >= 10) > 0.01 is n = 13.
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Your question is incomplete, but probably the complete question is :
Suppose that a brand of AA batteries reaches a significant milestone to their death on average after 7.36 hours, with standard deviation of 0.29 hours. Assume that when this milestone occurs follows a normal distribution.
(a) Calculate the probability that a battery does not reach this milestone in its first 8 hours of usage.
(b) Suppose that the company wants to sell a pack of n batteries of which (at least) 10 will last until 7.5 hours of usage. If n 12, what is the probability of this goal being met?
(c) How many batteries n should be in the package in order for the probability to exceed 1%? Give the smallest number n which works.
one of four different prizes was randomly put into each box of a cereal. if a family decided to buy this cereal until it obtained at least one of each of the four different prizes, what is the expected number of boxes of cereal that must be purchased?
The expected number of boxes of cereal that must be purchased to obtain at least one of each of the four different prizes is 1.
Let X be the number of boxes of cereal that need to be purchased to obtain at least one of each of the four different prizes. We want to find E(X), the expected value of X.
To do this, we can use the concept of the geometric distribution. The probability of obtaining a new prize in a box of cereal is given by:
p = 4/4 = 1 (since there are four different prizes)
The probability of not obtaining a new prize in a box of cereal is
q = 1 - p = 0
Therefore, X follows a geometric distribution with parameter p = 1. The expected value of a geometric distribution with parameter p is
E(X) = 1/p
So in this case, we have
E(X) = 1/1 = 1
This means that on average, the family will need to purchase one box of cereal to obtain at least one of each of the four different prizes.
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Some of the dimensions of a house are shown below.
Calculate the length u.
Give your answer in metres to 2 d.p.
56°
1.65 m
u
43°
Not drawn accurately
Using trigonometric relations we can see that u = 4.28m
How to find the length of u?First we can find the length of the shared side using the trigonometric relation:
tan(56°) = x/1.65m
1.65m*tan(56°) = x
2.45m = x
Then the length of the bottom side of the right triangle in the right side is iven by:
tan(43°) = 2.45m/y
Solving for y:
y = 2.45m/tan(43°)
y = 2.63m
Then the length of u is:
u = 1.65m + 2.63m = 4.28m
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Ava sells pottery at a market. Each piece of pottery costs $4.50 to make. Ava marks up the pottery by 250%. She then decides to have a sale of 30% off the retail price. What is the discounted price of each piece of pottery?
Thus, the discounted price on the retail price of each piece of pottery is found to be: Discounted price = $11.025.
Explain about the discounted price?The interest rate that is adjusted to the projected cash flows of either an investment to determine its present value is referred to as the discount rate. The expected rate of return on investment that businesses or investors anticipate. The viability of an investment can be determined by computing the net present value via discounting.
Cost price = $4.50
Percentage increase = 250%.
Marked price = 4.50 + 2.5*4.50
Marked price = $15.75
Discount = 30%
Discounted price = 15.75 - 0.30*15.75
Discounted price = $11.025
Thus, the discounted price on the retail price of each piece of pottery is found to be: Discounted price = $11.025.
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From the top of an 18-meter lighthouse, the angle of depression to sight a boat is 4°. What is the distance between the boat and the base of the lighthouse, to the nearest tenth?
ASAP TIMED
Step-by-step explanation:
The side opposite to the 4 degree angle is 18 m
The side adjacent the 4 degree angle is x
tan(4) = opposite / adjacent
adjacent = opposite / (tan(4))
adjacent = 18 / tan(4)
adjacent = 257.41