Question

A trade magazine routinely checks the​ drive-through service times of​ fast-food restaurants. An 80​% confidence interval that results from examining 576 customers in one​ fast-food chain's​ drive-through has a lower bound of 178.0 seconds and an upper bound of 181.0 seconds. What does this​ mean?

Answer 1

This means that we are 80% confident that the mean drive- through service time of fast food service is between 178.0 seconds and 181.0 seconds

Explanation:

A confidence Interval tells us that where the true value of parameter lies with certain confidence, It has a lower limit and an upper limit in this case it means with a confidence of 80% the mean drive- through service time of fast food service is between 178.0 seconds and 181.0 seconds

Answer 2

This means that we are 80% confident that the mean of the drive-through service time is between 178.0 seconds and 181.0 seconds. This conclusion was obtained after examined 576 customers. If you want a greater % of confidence you will have to lower the lower bound and increase the upper bound