Exhibit 9-4
The manager of a grocery store has taken a random sample of 100 customers. The average length of time it took the customers in the sample to check out was 3.1 minutes with a standard deviation of 0.5 minutes. We want to test to determine whether or not the mean waiting time of all customers is significantly more than 3 minutes.
-Refer to Exhibit 9-4. The test statistic is
A)1.96
B)1.64
C)2.00
D)0.056

Question

Quizplus · Accepted Answer

The test statistic is calculated using the formula: (sample mean - population mean) / (standard deviation / sqrt(sample size)). Here, it is (3.1 - 3) / (0.5 / sqrt(100)) = 2.00.

Exhibit 9-4 The Manager of a Grocery Store Has Taken a Random