Question

A trade magazine routinely checks the​ drive-through service times of​ fast-food restaurants. Upper A A 90 90​% confidence interval that results from examining 691 691 customers in one​ fast-food chain's​ drive-through has a lower bound of 161.9 161.9 seconds and an upper bound of 165.5 165.5 seconds. What does this​ mean? Choose the correct answer below. A. One can be 90 90​% confident that the mean​ drive-through service time of this​ fast-food chain is between 161.9 161.9 seconds and 165.5 165.5 seconds. B. One can be 90 90​% confident that the mean​ drive-through service time of this​ fast-food chain is 163.7 163.7 seconds. C. There is a a 90 90​% probability that the mean​ drive-through service time of this​ fast-food chain is between 161.9 161.9 seconds and 165.5 165.5 seconds. D. The mean​ drive-through service time of this​ fast-food chain is 163.7 163.7 seconds 90 90​% of the time.

Answer 1

Explanation:

Confidence interval gives possible estimate (range of values) that could contain the population proportion. Confidence level does not not mean probability. It only tells how confident we are that that the population proportion lies within the confidence interval.

Since we were told that the confidence interval has a lower bound of 161.9 seconds and an upper bound of 165.5 seconds, therefore, the correct option for the given situation is

A. One can be 90​% confident that the mean​ drive-through service time of this​ fast-food chain is between 161.9 seconds and 165.5 seconds.