A local eat-in pizza restaurant wants to investigate the possibility of starting to deliver pizzas. The owner of the store has determined that home delivery will be successful only if the average time spent on a delivery does not exceed 30 minutes. The owner has randomly selected 17 customers and delivered pizzas to their homes in order to test whether the mean delivery time actually exceeds 30 minutes. What assumption is necessary for this test to be valid?
A) The population of delivery times must have a normal distribution.
B) The population variance must equal the population mean.
C) The sample mean delivery time must equal the population mean delivery time.
D) None. The Central Limit Theorem makes any assumptions unnecessary.

Question

Quizplus · Accepted Answer

The assumption necessary for this test to be valid is that the population of delivery times must have a normal distribution, especially since the sample size is small (n=17).

A Local Eat-In Pizza Restaurant Wants to Investigate the Possibility