A sample of 100 bank customer waiting times are given in the following table:

Waiting Times (in Minutes) for the Bank Customer Waiting Time Case
5.2	4.3	2.8	6.0	11.5	9.2	9.4
6.0	5.5	5.1	4.6	6.2	7.5	8.9
5.2	.0	5.0	6.0	6.6	9.7	7.1
.6	8.7	7.0	4.9	4.0	7.3	.2
5.0	1.3	6.0	5.5	5.3	8.4	1.7
5.9	7.5	5.6	5.5	5.6	8.8	2.0
3.2	6.4	5.4	5.2	5.9	8.0	2.6
5.3	2.2	6.6	4.2	4.1	10.7	1.3
6.5	10.7	4.2	5.7	6.8	7.5	2.8
4.4	4.5	4.3	6.6	5.4	9.6	1.3
5.0	.7	5.7	4.1	5.1	8.5
6.9	11.8	5.2	4.7	7.0	8.0
8.7	3.2	6.6	6.9	6.8	9.6
3.0	6.7	5.8	4.4	4.2	7.6
8.9	3.2	5.8	6.8	7.6	8.8

A sample of 100 bank customer waiting times are given in the following table:

The mean and the standard deviation of the sample of 100 bank customer waiting times arexx= 5.773 and s = 2.482.

(a)What does the histogram inFigure 2.16say about whether the Empirical Rule should be used to describe the bank customer waiting times?

(b)Use the Empirical Rule to calculate estimates of tolerance intervals containing 68.26 percent, 95.44 percent, and 99.73 percent of all possible bank customer waiting times.(Round your answers to 3 decimal places. Negative amounts should be indicated by a minus sign.)

(c)Does the estimate of a tolerance interval containing 68.26 percent of all waiting times provide evidence that at least two-thirds of all customers will have to wait less than 9 minutes for service?

(d)How do the percentages of the 100 waiting times that actually fall into the intervals [xxs], [xx 2s], and [xx 3s] compare to those given by the Empirical Rule? Do these comparisons indicate that the statistical inferences you made in partsbandcare reasonably valid?(Round your answers to the nearest whole number.)

FIGURE 2.16 Minitab Frequency Histogram of the 100 Walting Times (for Exercise 2.22) Histogram of Waiting Times 18 17 16 16 14 12 Frequency 8 8 7 ONDOOONE 4 2 2 4 6 8 10 12 Waiting Time (in minutes)