The following data are the ages (in years) at diagnosis for 20patients under treatment for meningitis: 18 18 25 19 23 20 69 18 2118
20 18 18 20 18 19 28 17 18 18
(a) . Calculate and interpret the values of the samplemean, variance, and standard deviation.
(b) . Compute the sample median. Why might yourecommend it as a measure of centre rather than the sample mean?2
(c) . Compute the upper fourth, the lower fourth, andthe fourth spread. (d) . Illustrate the center, spread,and symmetry or skewness of this data using a horizontal modifiedboxplot.
