This question is incomplete, the complete question is;
Customers arrive at a movie theater at the advertised movie time only to find that they have to sit through several previews and preview ads before the movie starts. Many complain that the time devoted to previews is too long (The Wall Street Journal, October 12, 2012). A preliminary sample conducted by The Wall Street Journal showed that the standard deviation of the amount of time devoted to previews was 4 minutes. Use that as a planning value for the standard deviation in answering the following questions. Round your answer to next whole number,
a) If we want to estimate the population mean time for previews at movie theaters with a margin of error of 75 seconds, what sample size should be used? Assume 95% confidence.
b) If we want to estimate the population mean time for previews at movie theaters with a margin of error of 1 minute, what sample size should be used? Assume 95% confidence.
Answer:
a) the required Sample Size is 40
b) the required Sample Size is 62
Step-by-step explanation:
Given the data in the question;
standard deviation σ = 4 minutes
a)
margin of error E = 75 seconds = ( 75 / 60 )minutes = 1.25 minutes
And 95% confidence.
Now, Critical Value of z for 0.95 confidence interval;
∝ = 1 - 0.95 = 0.05
[tex]Z_{\alpha /2[/tex] = 1.96
so, sample size n will be;
n = [ [tex]Z_{\alpha /2[/tex] × σ/E ]²
we substitute;
n = [ 1.96 × (4/1.25) ]²
n = [ 1.96 × 3.2 ]²
n = [ 6.272 ]²
n = 39.338
Since we referring to a number of sample, its approximately becomes 40
Therefore, the required Sample Size is 40
b)
margin of error E = 1 minutes
And 95% confidence.
Now, Critical Value of z for 0.95 confidence interval;
∝ = 1 - 0.95 = 0.05
[tex]Z_{\alpha /2[/tex] = 1.96
so, sample size n will be;
n = [ [tex]Z_{\alpha /2[/tex] × σ/E ]²
we substitute;
n = [ 1.96 × (4/1) ]²
n = [ 1.96 × 4 ]²
n = [ 7.84 ]²
n = 61.466
Since we referring to a number of sample, its approximately becomes 62
Therefore, the required Sample Size is 62
Find the quotient: 28 ÷ 4 2/3
Answer:
6
Step-by-step explanation:
Answer:
6
Step-by-step explanation:
Is the line a good fit for the data points plotted in the scatter plot below?
If Bill hiked 6.5 miles at a rate of 10.4 mph, how long did it take him to complete his hike?
Answer:
I think it depends how far bill wants to hike..
Step-by-step explanation:
Write 7 as a fraction with 3 in the denominator
Answer:
7/3
Step-by-step explanation:
7 is in numerator's and 3 is in denominator's position.
PLSSSSSSSSSSS ASAP!!!!! Find the area of the figure shown below.
Answer:
54 square ft
Step-by-step explanation:
Find missing sides:
8+6 = 14
9-6 = 3
Find area of full rectangle:
9×8 = 72
Find the area of the missing part of the full rectangle
3×6 = 18
Find the area of the actual shape:
72-18 = 54
Area = 54 square ft
b)
Simplify 5x2 - x2
Answer: the answer is 4x^2
Step-by-step explanation:
hope it help
Pls help math lol. Yeah
Answer:
X = 65 degrees
Step-by-step explanation:
180 = 70 + 45 + X
180 = 115 + X
X = 65 degrees
Find the area of the shape shown below.
Answer:
8 units²
Step-by-step explanation:
What you have is a square with two triangles. We will break them apart, calculate the area and then add them together.
Square: A = l · w
2 · 2 = 4 un²
Triangle: A = (b · h) ÷ 2
(2 · 2) ÷ 2 = 2 un²
4 un² + 2 un² + 2 un²
8 un²
The times that a cashier spends processing individual customers' orders are independent random variables with mean 3.5 minutes and standard deviation 3 minutes. Find the number of customers n such that the probability that the orders of all n customers can be processed in less than 2 hours, is approximately 0.1. (Round your answer to the nearest integer.)
Answer:
26 customers
Step-by-step explanation:
First: determine the z score from standard normal probability table with an indicative area of 0.1
Z-score from probability table = - 1.28
mean = 3.5 minutes
std = 3 minutes
next determine the Z-score based on the information given in the question
Z = ( std - mean ) / processing time
= ( 3 - 3.5 ) / 2 = -0.25
Finally determine the number of customers
N = [tex](\frac{-1.28}{-0.25} )^2[/tex] = 1.6384 / 0.0625 = 26.21 ≈ 26 customers
What are the dimensions of the rectangle shown on the coordinate plane?
w
+2
6
The base is 3 units and the height is 9 units.
O The base is 9 units and the height is 4 units.
O The base is 10 units and the height is 4 units.
O The base is 11 units and the height is 6 units.
A babysitter earns the same amount per hour. She earned $36 for 3 hours of babysitting. Which equation describes the relationship between x, the number of hours spent babysitting, and y, the total amount
in dollars earned?
Answer:
y= 12x
Step-by-step explanation:
36/3=12
12× x =y
________________________
Caroline has a rock stuck in her Jeep’s tire
Answer:
oh no
Step-by-step explanation:
sorry about that I guess
PLZ HELPPPPPPPPPPP MEEEEEEEEE
21. A Figure is shown below.
What is the area of the figure, in square inches?
Answer:
[tex]36+27\pi\:\mathrm{in^2}[/tex]
Step-by-step explanation:
The figure consists of a square and a sector. We can add the areas of the square and sector to get the total area of the figure.
The area of a sector with measure [tex]\theta[/tex] in a circle of radius [tex]r[/tex] is equal to [tex]\frac{\theta}{360}\cdot r^2\pi[/tex]. Since there are 360 degrees in a circle and 90 degrees in each corner of a square, the measure of the sector is [tex]270^{\circ}[/tex].
Thus, its area is:
[tex]\frac{270}{360}\cdot6^2\cdot pi=\frac{3}{4}\cdot 6^2\cdot \pi=27\pi[/tex].
The area of a square with side length [tex]s[/tex] is given by [tex]s^2[/tex]. Therefore, the area of the circle is [tex]6^2=36[/tex] and the total area of the figure is [tex]\boxed{36+27\pi\:\mathrm{in^2}}[/tex]
Answer: 36+27in2
Step-by-step explanation:
Which of the following names the figure in the diagram below?
A. pentagon
B. prism
C. triangle
D. polygon
E.pyramid
F. square
Answer: Prism
Step-by-step explanation:
Charlotte has 30 beads. She has 8 more red beads than blue beads. Which equation represents this situation? Please help :(
Answer:
The second answer choice is right
Step-by-step explanation:
Which figure is a triangular prism?
Answer:
B
Step-by-step explanation:
A triangular prism is described as a triangle stretched on the third dimension, so the bottom of it will be a square or a rectangle. Two of the sides will also be squares or rectangles. B is the only option that applies to BOTH of these requirements.
Answer:
B
hope it helped !!
which best describes a rectangle with diagonals that are perpendicular
Answer: If a parallelogram has diagonals that are perpendicular, it is a rhombus. … This definition can also be stated as: A square is a quadrilateral that is also a rectangle and a rhombus.
Step-by-step explanation:
Calculate the volume of this can of baked beans:
Choices:
120.95cm3
38.5cm3
77cm3
423.32cm3
Answer:
423.32cm³
Step-by-step explanation:
Volume of a cylinder = [tex]V=\pi r^2h[/tex]
where r = radius and h = height
Given height = 11 cm
Given radius = 3.5 cm
* plug in these values into the formula *
[tex]V=\pi 3.5^211\\3.5^2=12.25 \\12.25\pi =38.48\\34.48*11=423.32\\V=423.32[/tex]
So we can conclude that the answer would be D
Find the length of arc AB.
Answer:
11.17
Step-by-step explanation:
arc length = 2πr(θ/360)
= 2π(8)(80/360)
= 11.1701072...
= 11.17 to nearest hundredth
Type the integer in the box.
Solve:: t/2 + 10 =-40
Answer:
t = -100
Step-by-step explanation:
Simplify to isolate t:
[tex]\frac{t}{2}+10-10=-40-10[/tex]
[tex]\frac{t}{2} * \frac{2}{1} = -50 * 2[/tex]
[tex]t = -100[/tex]
A curve passes through a point P(0, 3) and has the property that slope of curve at every point P is twice the y-coordinate of point P. Use the concept of exponential growth function to find the equation of curve.
Answer:
The equation of curve is [tex]y = 3\cdot 7.389^{x}[/tex].
Step-by-step explanation:
The exponential growth function is represented by the expression described below:
[tex]y = a\cdot b^{x}[/tex] (1)
Where:
[tex]x[/tex] - Independent variable.
[tex]y[/tex] - Dependent variable.
[tex]a[/tex] - Initial value of [tex]y[/tex].
[tex]b[/tex] - Base.
By deriving (1), we obtain an expression for the slope of the curve:
[tex]y' = a\cdot b^{x} \cdot \ln b[/tex] (2)
If we know that [tex]x = 0[/tex], [tex]y = 3[/tex] and [tex]y' = 6[/tex], then we have the following system of equations:
[tex]a = 3[/tex] (3)
[tex]a\cdot \ln b = 6[/tex] (4)
By (3) in (4):
[tex]3\cdot \ln b = 6[/tex]
[tex]\ln b = 2[/tex]
[tex]b = e^{2}[/tex]
[tex]b = 7.389[/tex]
Therefore, the equation of curve is [tex]y = 3\cdot 7.389^{x}[/tex].
a cylinder has a diameter of 12 and height of 12. the volume of the cylinder is:
A. 1728π cubic units
B. 288π cubic units
C. 144π cubic units
D. 432π cubic units
1+1 why does my dog not love me?
Answer:
2
Step-by-step explanation:
your dog doesn't love you because it saw what you did. it knows. be cautious around your dog from now on. it knows more than you think and sees all. I'm warning you
1. The exact value of cos60
is
A) 3
3 B) 2
3 C) 2
2 D) 2
1 E) none of the above
Which temperature is most likely to be a data point for both cities if in city
one the average temperature is 70 degrees and in the second city the
average temperature is 80 degrees
O 150
O 75
0 75.5
How do you solve 3(15.9 - 3.9)
Step by step? I need help
Answer:
36
Step-by-step explanation:
3(15.9 - 3.9)
3 · (15.9 - 3.9)
3(15.9) - 3(3.9)
47.7 - 3(3.9)
47.7 - 11.7
36
Answer:
I believe the answer is 15
Step-by-step explanation:
15.9 - 3.9 (line up the decimals correctly)
then subtract it and you get 12.0
add 12.0 + 3 (under the 2)
12.0
+3
and you get 15 as your answer :)
Evaluate f(x) = 2x - 7 when x = 8.
Answer:
9
Step-by-step explanation:
Substitute 8 in place of x
f(x) = 2*8-7
f(x) = 9
Answer:
9
Step-by-step explanation:
plug in 8 where x is so it would look like
2(8)-7 = 9
do 2 *8 first which is 16
then do 16-7 which gives you 9
Your pool is 80 ft long by 40 ft wide and the depth is 3ft to 8ft what is the pool volume?
Answer:
Since there are 7.5 gallons in each cubic foot, multiply the cubic feet of the pool by 7.5 to arrive at the volume of the. 3.14 x 25 ft x 3 ft x 7.5 = 1766.25 gallons
Step-by-step explanation:
Find the perimeter of a rectangle with a base of 12 ft and a height of 5 ft.
Answer:
P=34ft
Step-by-step explanation:
Solution
P=2(l+w)=2·(12+5)=34ft