A mail-order business prides itself in its ability to fill customers' orders in less than six calendar days,on average.Periodically,the operations manager selects a random sample of customer orders and determines the number of days required to fill the orders.On one occasion when a sample of 39 orders was selected,the average number of days was 6.65 with a sample standard deviation of 1.5 days.Calculate the appropriate test statistic to test the hypotheses.
A)2.71
B)16.90
C)0.65
D)-2.71
E)3.31

Question

Quizplus · Accepted Answer

The correct test statistic is 2.71. This is calculated by taking the difference between the sample mean and the hypothesized mean (6 days) and dividing by the standard error of the mean (1.5 days / sqrt(39)).

A Mail-Order Business Prides Itself in Its Ability to Fill