Answer:
(a) An investigation of whether taking aspirin reduces one’s chance of having a heart attack.
Experimental
Neither blind nor double-blind (unless a placebo is being administered to some participants).
(b) An investigation of whether babies born into poor families (family income below $25,000) are more likely to weigh less than 5.5 pounds at birth than babies born into wealthy families (family income above $65,000).
Observational
There is no blinding issue here.
(c) An investigation of whether the size of the midsagittal plane of the anterior commissure (a part of the brain) of a man is related to the sexual orientation of the man.
Observational
There is no blinding issue here.
Step-by-step explanation:
An observational study happens where some variables are observed to determine their correlations. On the other hand, in experimental studies, the researcher controls certain variables to determine causality. Therefore, an experimental study provides evidence of cause and effect, like in (a) above.
The constant of proportionality of this table is
Cups of
blue paint
cups of
yellow paint
2 10
1
Answer:
Step-by-step explanation:
1/2
A box is formed by cutting squares from the four corners of a sheet of paper and folding up the sides.
Suppose the paper is 7"-wide by 9"-long.
a. Estimate the maximum volume for this box?
b. What cutout length produces the maximum volume?
Answer:
B
Step-by-step explanation:
To answer this question it is necessary to find the volume of the box as a function of "x", and apply the concepts of a maximum of a function.
The solution is:
a) V (max) = 36.6 in³
b) x = 1.3 in
The volume of a cube is:
V(c) = w×L×h ( in³)
In this case, cutting the length "x" from each side, means:
wide of the box ( w - 2×x ) equal to ( 7 - 2×x )
Length of the box ( L - 2×x ) equal to ( 9 - 2×x )
The height is x
Then the volume of the box, as a function of x is:
V(x) = ( 7 - 2×x ) × ( 9 -2×x ) × x
V(x) = ( 63 - 14×x - 18×x + 4×x²)×x
V(x) = 4×x³ - 32×x² + 63×x
Tacking derivatives, on both sides of the equation
V´(x) = 12×x² - 64 ×x + 63
If V´(x) = 0 then 12×x² - 64 ×x + 63 = 0
This expression is a second-degree equation, solving for x
x₁,₂ = [ 64 ± √ (64)² - 4×12*63
x₁ = ( 64 + 32.74 )/ 24
x₁ = 4.03 this value will bring us an unfeasible solution, since it is not possible to cut 2×4 in from a piece of paper of 7 in ( therefore we dismiss that value)
x₂ = ( 64 - 32.74)/24
x₂ = 1.30 in
The maximum volume of the box is:
V(max) = ( 7 - 2.60) × ( 9 - 2.60)×1.3
V(max) = 4.4 × 6.4 × 1.3
V(max) = 36.60 in³
To chek for maximum value of V when x = 1.3
we find the second derivative of V V´´, and substitute the value of x = 1.3, if the relation is smaller than 0, we have a maximum value of V
V´´(x) = 24×x - 64 for x = 1.3
V´´(x) = 24× 1.3 - 64 ⇒ V´´(x) < 0
Then the value x = 1.3 will bring maximum value for V
Related Link: https://brainly.com/question/13581879
find the values of the six trigonometric functions for angle theta in standard position if a point with the coordinates (1, -8) lies on its terminal side
Answer:
cosФ = [tex]\frac{1}{\sqrt{65}}[/tex] , sinФ = [tex]-\frac{8}{\sqrt{65}}[/tex] , tanФ = -8, secФ = [tex]\sqrt{65}[/tex] , cscФ = [tex]-\frac{\sqrt{65}}{8}[/tex] , cotФ = [tex]-\frac{1}{8}[/tex]
Step-by-step explanation:
If a point (x, y) lies on the terminal side of angle Ф in standard position, then the six trigonometry functions are:
cosФ = [tex]\frac{x}{r}[/tex]sinФ = [tex]\frac{y}{r}[/tex]tanФ = [tex]\frac{y}{x}[/tex]secФ = [tex]\frac{r}{x}[/tex]cscФ = [tex]\frac{r}{y}[/tex]cotФ = [tex]\frac{x}{y}[/tex]Where r = [tex]\sqrt{x^{2}+y^{2} }[/tex] (the length of the terminal side from the origin to point (x, y)You should find the quadrant of (x, y) to adjust the sign of each function∵ Point (1, -8) lies on the terminal side of angle Ф in standard position
∵ x is positive and y is negative
→ That means the point lies on the 4th quadrant
∴ Angle Ф is on the 4th quadrant
∵ In the 4th quadrant cosФ and secФ only have positive values
∴ sinФ, secФ, tanФ, and cotФ have negative values
→ let us find r
∵ r = [tex]\sqrt{x^{2}+y^{2} }[/tex]
∵ x = 1 and y = -8
∴ r = [tex]\sqrt{x} \sqrt{(1)^{2}+(-8)^{2}}=\sqrt{1+64}=\sqrt{65}[/tex]
→ Use the rules above to find the six trigonometric functions of Ф
∵ cosФ = [tex]\frac{x}{r}[/tex]
∴ cosФ = [tex]\frac{1}{\sqrt{65}}[/tex]
∵ sinФ = [tex]\frac{y}{r}[/tex]
∴ sinФ = [tex]-\frac{8}{\sqrt{65}}[/tex]
∵ tanФ = [tex]\frac{y}{x}[/tex]
∴ tanФ = [tex]-\frac{8}{1}[/tex] = -8
∵ secФ = [tex]\frac{r}{x}[/tex]
∴ secФ = [tex]\frac{\sqrt{65}}{1}[/tex] = [tex]\sqrt{65}[/tex]
∵ cscФ = [tex]\frac{r}{y}[/tex]
∴ cscФ = [tex]-\frac{\sqrt{65}}{8}[/tex]
∵ cotФ = [tex]\frac{x}{y}[/tex]
∴ cotФ = [tex]-\frac{1}{8}[/tex]
Suppose that the probability that a person books a hotel using an online travel website is 0.68. For the question that follows, consider a sample of fifteen randomly selected people who recently booked a hotel.
What is the probability that at least fourteen out of fifteen people used an online travel website when they booked their hotel? Round to three decimal places.
A.0.028
B.0.025
C.0.323
D.0.978
Answer:
the answer is d because 0.978 cool number like yaaaa.
Step-by-step explanation:
1. You are eating on a Tootsie Roll Lollipop that is in the shape of a sphere. It is giving up volume at a steady rate of 0.25 in3 /min. How fast will the radius be decreasing when the Tootsie Roll Pop is .75 inches across?
Answer:
Step-by-step explanation:
Since the Tootsie Roll lollipop is a sphere
volume of sphere= [tex]\frac{4}{3}piR^3[/tex] = -0.25 [tex]in^3/min[/tex]
the negative sign indicates that the volume is decreasing
upon differentiating
as the diameter given is =0.75 so radius will be = 0.375
[tex]dV/dt = 4piR^2*dR/dt[/tex]
so [tex]dR/dt = 0.25/4*3.14 *(0.375)^2[/tex]
So the radius is decreasing at the rate of dR/dt= 0.142in/min
Jackson has 429 matchbox cars in his collection. If 4 out of 9 are blue cards, how many are not blue
which number is the same as 0.000 000 1: 10^7 or 10^-7
Answer:
= 1 × 10^-7
(scientific notation)
= 1e-7
(scientific e notation)
= 100 × 10^-9
(engineering notation)
(billionth; prefix nano- (n))
= 0.0000001
(real number)
Step-by-step explanation:
10^7 = 10000000
please help!! I'm really confused
Answer:
Point a is correct.
Step-by-step explanation:
hope I helped.
Consider the experiment of selecting a playing card from a deck of 52 playing cards. Each card corresponds to a sample point with a 1 52 probability.
Required:
a. List the sample points in the event a jack is selected.
b. List the sample points in the event a club is selected.
c. List the sample points in the event a face card ( jack, queen, or king) is selected.
d. Find the probabilities associated with each of the events in parts (a), (b), and (c).
Answer:
Kindly check explanation
Step-by-step explanation:
A deck of card:
Number of hearts = 13
Diamond = 13
Spade = 13
Club = 13
Each of heart, club diamond and spade has is numbered from (2,3,4,5,6,7,8,9,10,Ace, queen, Jack, king)
Hence, a club, diamond, spade and heart has one of each of the above numbers.
a. List the sample points in the event a jack is selected.
Jack : ( heart, club, diamond, spade)
B.) club is selected :
Cub : (Ace, 2, 3,4,5,6,7,8,9,10,king,queen,jack)
C)
Jack : ( heart, club, diamond, spade)
Queen : (heart, club, diamond, spade)
King : (heart, club, diamond, spade)
D) probability = required outcome / Total possible outcomes
P(jack selected) = 4 /52 = 1/13
P(club selected). = 13/52 = 1/4
P(face card selected) = 12 / 52 = 3/13
Please help!!!- Find the measure of the angle in bold.
Need help to figure out to solve this.
Answer:
11x-6+(19x+6)=180°
11x+19x-6+6=180°
30x=180
x=180/30
x=6
it means that
19x+6=19*6+6=114+6=120°
Solve:
a.) 5(x - 2) > -15
AND
b.) x/1 - 9 < -10
Answer:
a.) x>-1
b.) x/1 - 9 < -10
Step-by-step explanation:
a.)
5(x - 2) > -15
(divide both sides)
x-2>-3
(move the constant to the right)
x>-3+2
(calculate)
x>-1
(answer)
b.)
x/1 - 9 < -10
(divide)
x-9<-10
(move the constant to the right)
x<-10+9
(calculate)
x/1 - 9 < -10
(answer)
Find the selling price of each item original plate price of gold fish at $7.65 discount 10%
Answer:
6.88 is what I think you're looking for
Step-by-step explanation:
Herman is standing on a ladder that is partly in a hole. He starts out on a rung that is 6 feet under ground, climbs up 14 feet, then climbs down 11 feet. What is Herman’s final position, relative to ground level?
Answer:
Are there answers
Step-by-step explanation:
Answer:
answer
Herman is standing on a ladder that is partly in a hole. He starts out on a rung that is 6 feet under ground, climbs up 14 feet, then climbs down 11 feet. ...
A car sharing service offers a membership plan with a $50 per month fee that includes 10 hours of driving each month and charges $9 for each additional hour
(A) Write a piecewise definition of the cost F(x) for a month in which a member uses a car for x hours
(B) Graph F(x) for 0 < x s 15
(C) Find lim x--->10 F(x), lim x--->10F(x), and lim x--->10F(x), which- ever exist.
Answer:
A) F(x) = 50 + ( x - 10 )*9
B) Graph
C) lim ( x ⇒ 10) F(x) = 50
Step-by-step explanation:
A) F(x) = 50 + ( x - 10 )*9 since the first 10 hours are included in initial fee
B) In Annex
C) lim (x ⇒ 10) F(x) = 50 + ( 10 -10)*9
lim ( x ⇒ 10) F(x) = 50 + 0
lim ( x ⇒ 10) F(x) = 50
A map has a scale of 2 in: 6 mi. If Clayton
and Centerville are 10 in apart on the map
then how far apart are the real cities?
The giber family purchased a house for 127,000 the first five years they paid off 12,000 each year . How much money do they still owe on the house ?
Answer:
dndnfhhfbdhdndndnmdmdndndnen
Find the product of (18k+ 2m)(m + k)
Answer:
18k^2+2m^2+20km
Step-by-step explanation:
PLEASE HELP IM TIMEZ) What is the value of the arithmetic series below? A. B. C. D.
Answer:
id say its C but I'm not sure
A jewelry store is having a 45% off sale for all necklaces. During this sale, what is the cost of a necklace that regularly costs $59.98?
Answer:
32.99
Step-by-step explanation:
59.98(45%)=26.99
59.98-26.99=32.99
Answer:
$32.99, the discount took off $26.99.
Step-by-step explanation:
Good luck!
Complete the point-slope equation of the line through (2,3)(7,4)
y-4=
What is the measure of angle F?
E. 20
D. 90
F.?
Answer:
the answer would be 70 because you take 90-20 and you get 70. you have a 90 degree angle is what you're working on right now
Step-by-step explanation:
I need help. Is this right????
Answer: (I can only see stage 1 and 2 fully) Stage 1: 2 Stage 2: 4
Step-by-step explanation:
Answer:
Step-by-step explanation:
0 = 0
1 = 2
2 = 4
3 = 6
20 = 40
Which best describes the solution set of the compound inequality below? 2 + x ≤ 3x – 6 ≤ 12 4 ≤ x ≤ 9 4 ≤ x ≤ 6 –2 ≤ x ≤ 2 –2 ≤ x ≤ 3
Answer:
Im sure you dont need this anymore but in case someone else does, im pretty sure the answer is B
Answer:
B is tha right answer
Step-by-step explanation:
a diver descended 84 feet in 6 minutes. What was the divers change in depth per minute? Write and expression with a solution
Answer:
14 depth per minute
Step-by-step explanation:
84/6 = 14
PLEASE ANSWER I WILL GIVE YOU BRAINLIEST!
Name the points which satisfy the conditions. In the second quadrant
9514 1404 393
Answer:
C, M
Step-by-step explanation:
The second quadrant is the upper left quadrant. There, x-values will be negative and y-values will be positive.
__
Point G is on the boundary with the 3rd quadrant, so is probably not considered to be in either of those quadrants.
Answer: C M
Step-by-step explanation:
What is the area of a rectangle with sides measuring 2x+3 and 3x-1 feet
what is 4/6+2/3.?(these are fractions, you're just adding fractions)
Answer:
4/3
Step-by-step explanation:
Multiply 2 by 2, and get 4, then we multiply 3 by 2 and get 6.
Since our denominators match, we can add the numerators. 4 + 4 = 8. That gives us the sum, which is 8/6. Then you divide by 2. So 8/6 / 2 gives you 4/3.
Answer:
4/3 or 1 1/3
Step-by-step explanation:
1. 4/6 + 2/3
2. 4/6 + 4/6 You have to find the LCM (least common multiple) of the two denominators. In this case it would be 6. You have to multiply 3 by 2 to get 6. What you do to the bottom you also do to the top so you have to also multiply the numerator (2) by 2.
3. 4/3 or 1 1/3 Afterward, you just have to add straight across without changing the denominator and then if you need to simplify you simplify. Without simplifying, you would get 8/6, but, most teachers will mark it as wrong if you don't simplify. You can then change the improper fraction into a mixed number depending on what your teacher wants.
An item has a listed price of $80. If the sales tax rate is 8%, how much is the sales tax (in dollars)?
Answer:
$6.40
Step-by-step explanation:
u have to multiply 80 by 0.08 (tax percent in decimal form)
Answer:
$6.4
Step-by-step explanation:
all you have to do is find 8% of 80 by doing 8x8, which equals 64, then dividing by 10. That gives you 6.4. Then check it on a calculator to make sure you did it correctly
10a^2b^0 for a=–3, b=–8
Answer:
90Step-by-step explanation:
Substitute a = -3 and b = -8 to the expression 10a²b⁰:
10(-3)²(-8)⁰ = 10(9)(1) = 90
a⁰ = 1 for any real number
Answer:
90
Step-by-step explanation:
10a^2b^0
Let a=–3, b=–8
10 (-3)^2 ( -8)^0
10 * 9 *1
90
The life span of a graphing calculator manufactured by Texas Instruments has a normal distribution with a mean of 54 months and a standard deviation of 8 months. The company guarantees that any calculator that starts malfunctioning within 36 months of the purchase will be replaced by a new one. You apply the normal model and discover that this is approximately 1.22% of their graphing calculators. Texas Instruments has sold 75 million graphing calculators world- wide. How many of these would you expect to malfunction within 3 months (and thus need to be replaced)? Explain.
Answer:
The expected number of graphing calculators that malfunctions within 3 months and need to be replaced is 915,000.
Step-by-step explanation:
Let X represents the number of graphing calculator that starts malfunctioning within 36 months of the purchase and needs to be replaced by a new one.
It is provided that X follows a normal distribution with a mean of 54 months and a standard deviation of 8 months.
Also, using the normal model it was determined that 1.22% of graphing calculator manufactured by Texas Instruments malfunctions and needs replacement.
That is,
P (X) = 0.0122
Texas Instruments has sold 75 million graphing calculators world- wide.
Compute the expected number of graphing calculators that malfunctions within 3 months and need to be replaced as follows:
E (X) = n × P (X)
= 75 × 10⁶ × 0.0122
= 915000
Thus, the expected number of graphing calculators that malfunctions within 3 months and need to be replaced is 915,000.