Recall that Table 1.8 presents the waiting times for teller service during peak business hours of 100 randomly selected bank customers. Figures 3.9 and 3.11(b) give the MINITAB and Excel outputs of statistics describing the 100 waiting times.
a. Find the sample mean on the outputs. Does the sample mean provide some evidence that the mean of the population of all possible customer waiting times during peak business hours is less than six minutes (as is desired by the bank manager)? Explain your answer.
b. Find the sample median on the outputs. How do the mean and median compare? What does the histogram in Figure 2.16 tell you about why they compare this way?
Table 1.8

Figure 2.16

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Waiting Times (in Minutes) for the Bank Customer Waiting Time Case TABLE 1.8 1.6 6.2 6.6 54 5.6 4.9 5.1 3.9 4.6 2.5 6.5 8.3 6.4 8.6 6.3 4.2 5.8 3.4 2.9 9.3 10.9 3.2 5.6 7.9 6.5 4.4 1.1 7.2 7.3 2.3 4.5 7.2 074.1 6.1 3.8 5.4 .8 8.7 6.7 2.9 4.7 8.1 9.1 4.3 7.7 2.7 2.2 4.0 5.8 1.4 4 8.6 7.8 6.8 10.2 2.05.2 2.88.0 8.4 11.6 9.5 6.3 1.3 4.4 4.8 5.2 5.8 9.9 7.4 7.5 6.7 7.0 3.5 5.3 6.3 4.5 4.3 4.5 3.8 1.8 5.1 3.7 5.5 4.0 5.7 2.4 9.2 5.0 3.6 6.1 3.7 9.8 4.3 1.8 3.9 Histogram of Waiting Times 18-T 16 14 12 16 14 12 8 8 6 6 2 0 4 6 8 10 12 Waiting Time (in minutes)