Suppose a bank branch, located in a residential area, is connected with its service during the noon-to-1 pm lunch hour. The waiting times, in minutes, collected from a sample of 15 customers during this hour, are listed below.

9.64 5.98 7.98 5.85 8.76 3.83 8.01 8.38 10.39 6.73 5.68 4.11 6.15 9.93 5.57

Complete parts (a) through (d) below.
(a) Compute the mean and median.
(b) Compute the variance, standard deviation, range, coefficient of variation, and Z scores. Are there any outliers? Explain.
(c.1) Are there any outliers? Explain.

A. Yes, since there are no Z scores that are less than - 3.0 or greater than +3.0.
B. No, since there are no Z scores that are less than - 3.0 or greater than +3.0
C. No, since there is at least one Z score that is less than - 3.0 or greater than +3.0
D. Yes, since there is at least one Z score that is less than -3.0 or greater than +3.0 c).

(c.2) Are the data skewed? If so, how? Choose the correct response below.

A. Yes, the data are right-skewed because the mean is greater than the median.
B. Yes, the data are left-skewed because the mean is less than the median.
C. No, the data are not skewed because the mean and median are equal.

(d) As a customer walks into the branch office during the lunch hour, he asks the branch manager how long he can expect to wait. The branch manager replies, " Almost certainly less than 5 minutes." On the basis of the results of (a) through (c), evaluate the accuracy of this statement. Choose the correct response below.

A. Although both the mean and median are greater than 5 minutes, all values greater than 5 minutes have a Z score greater than +3.0, thus they are outliers. This means the branch manager's statement is accurate.
B. Since the mean and median are both greater than 5 minutes, the customer is likely to experience a waiting time in excess of 5 minutes.
C. Since the range of value is greater than 5 minutes, the customer is likely to experience a waiting time in excess of 5 minutes.