Question: Sandra Enright, of Techtronics Inc., has been examining the times required for stock pickers to fill orders requested from inventory. In the past, retrieval times followed a normal distribution with a mean value of 3.2 minutes. Sandra is concerned that recent changes to storage locations may have lengthened the average retrieval time. Sandra does not want to order a reorganization of storage locations without good evidence that the mean retrieval time has lengthened; however, she is willing to accept a 5% chance of making this error.

A random sample of retrieval times are recorded in the spreadsheet Q1 Stock picking.xlsx.

a) Calculate descriptive statistics for these data. Does it appear that the average retrieval time has increased?

b) Conduct a test of hypothesis appropriate for Techtronics’ situation, and make a specific recommendation regarding whether or not Sandra should order a storage reorganization.