A network provider investigates the load of its network. The number of concurrent users is recorded at fifty locations (thousands of people),
17.2 22.1 18.5 17.2 18.6 14.8 21.7 15.8 16.3 22.8
24.1 13.3 16.2 17.5 19.0 23.9 14.8 22.2 21.7 20.7
13.5 15.8 13.1 16.1 21.9 23.9 19.3 12.0 19.9 19.4
15.4 16.7 19.5 16.2 16.9 17.1 20.2 13.4 19.8 17.7
19.7 18.7 17.6 15.9 15.2 17.1 15.0 18.8 21.6 11.9
(a) Compute the sample mean, variance, and standard deviation of the number of concurrent users.
(b) Estimate the standard error of the sample mean.
(c) Compute the five-point summary and construct a boxplot.
(d) Compute the interquartile range. Are there any outliers?
(e) It is reported that the number of concurrent users follows approximately Normal distribution. Does the histogram support this claim