Question

# Suppose you work for Fender Guitar Company and you are responsible for testing the integrity of...

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)

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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:

 1) ( 0.4963 , 0.59844 )
 2) ( 0.46337 , 0.63137 )
 3) ( -0.46337 , 0.63137 )
 4) ( 0.36863 , 0.53663 )
 5) ( 0.48192 , 0.61281 )

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)

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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) HO: p ≥ 0.62 HA: p < 0.62
 2) HO: p = 0.62 HA: p ≠ 0.62
 3) HO: p > 0.62 HA: p ≤ 0.62
 4) HO: p < 0.62 HA: p ≥ 0.62
 5) HO: p ≤ 0.62 HA: p > 0.62

Question 6 (1 point)

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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) HO: p = 0.43 HA: p ≠ 0.43
 2) HO: p < 0.43 HA: p ≥ 0.43
 3) HO: p ≤ 0.43 HA: p > 0.43
 4) HO: p > 0.43 HA: p ≤ 0.43
 5) HO: p ≥ 0.43 HA: p < 0.43

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