Suppose you work for Fender Guitar Company and you are
responsible for testing the integrity of a new formulation of
guitar strings. To perform your analysis, you randomly select 51
'high E' strings and put them into a machine that simulates string
plucking thousands of times per minute. You record the number of
plucks each string takes before failure and compile a dataset. You
find that the average number of plucks is 6,398 with a standard
deviation of 286.12. A 95% confidence interval for the average
number of plucks to failure is (6,317.5, 6,478.5). From the option
listed below, what is the appropriate interpretation of this
interval?
Question 2 options:

1)

We cannot determine the proper interpretation of this
interval. 


2)

We are 95% confident that the average number of plucks to
failure for all 'high E' strings tested is between 6,317.5 and
6,478.5. 


3)

We are 95% confident that the proportion of all 'high E' guitar
strings fail with a rate between 6,317.5 and 6,478.5. 


4)

We are certain that 95% of the average number of plucks to
failure for all 'high E' strings will be between 6,317.5 and
6,478.5. 


5)

We are 95% confident that the average number of plucks to
failure for all 'high E' strings is between 6,317.5 and
6,478.5. 

Question 3 (1 point)
Saved
To design a new advertising campaign, Ford Motor Company would
like to estimate the proportion of drivers of the new Ford Fusion
that are women. In a random sample of 95 Fusion owners, 52 of them
were women. What is the 90% confidence interval estimating the
proportion of all drivers who are women?
Question 3 options:





3)

( 0.46337 , 0.63137 ) 





Question 4 (1 point)
Based on past data, the Student Recreation Center knew that the
proportion of students who prefer exercising outside over
exercising in a gym was 0.74. To update their records, the SRC
conducted a survey. Out of 67 students surveyed, 56 indicated that
they preferred outdoor exercise over exercising in a gym. The 95%
confidence interval is ( 0.7471 , 0.9245 ). Which of the following
statements is the best conclusion?
Question 4 options:

1)

The confidence interval does not provide enough information to
form a conclusion. 


2)

The proportion of students who have changed their exercise
habits from 0.74 is 95%. 


3)

We can conclude that the proportion of students who prefer
outdoor exercise is larger than 0.74. 


4)

We can claim that the proportion of students who prefer outdoor
exercise is smaller than 0.74. 


5)

We can not conclude that the proportion of students who prefer
outdoor exercise differs from 0.74. 

Question 5 (1 point)
Saved
A suggestion is made that the proportion of people who have food
allergies and/or sensitivities is 0.62. You believe that the
proportion is actually greater than 0.62. If you conduct a
hypothesis test, what will the null and alternative hypothesis
be?
Question 5 options:

1)

H_{O}: p ≥ 0.62
H_{A}: p < 0.62 


2)

H_{O}: p = 0.62
H_{A}: p ≠ 0.62 


3)

H_{O}: p > 0.62
H_{A}: p ≤ 0.62 


4)

H_{O}: p < 0.62
H_{A}: p ≥ 0.62 


5)

H_{O}: p ≤ 0.62
H_{A}: p > 0.62 

Question 6 (1 point)
Saved
As of 2012, the proportion of students who use a MacBook as
their primary computer is 0.43. You believe that at your university
the proportion is actually greater than 0.43. If you conduct a
hypothesis test, what will the null and alternative hypotheses
be?
Question 6 options:

1)

H_{O}: p = 0.43
H_{A}: p ≠ 0.43 


2)

H_{O}: p < 0.43
H_{A}: p ≥ 0.43 


3)

H_{O}: p ≤ 0.43
H_{A}: p > 0.43 


4)

H_{O}: p > 0.43
H_{A}: p ≤ 0.43 


5)

H_{O}: p ≥ 0.43
H_{A}: p < 0.43 
