need help on part a and part b please!

Management is interested in increasing the efficiency of processing purchase orders. The time to process purchase orders, in days, was observed for 31 randomly selected customers and is shown in Table 4-6. Following a detailed study of the process, certain recommendations were adopted. Twenty-six customers were randomly selected and their purchase order processing times are shown after the process improvement changes. (a) Find the mean, standard deviation, skewness coefficient, kurtosis coefficient, and interquartile range of the processing time prior to process changes and comment on the values. (b) Find the mean, standard deviation, skewness coefficient, kurtosis coefficient, and interquartile range of the processing time after the process changes and comment on the values. Customer Customer Before Change Processing Time 9.7 11.2. 10.5 8.3 9.2 8.8 10.4 11.6 10.1 9.6 8.8 12.3 10.9 11.1 1 2 3 4 5 6. 7 8 9 10 11 12 13 After Change Processing Time 7.6 8.3 7.9 8.6 8.3 6.2 9.1 8.8 8.4 7.5 8.5 1 2. 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 11.6 12.3 10.2 10.7 11.3 9.1 9.9 8.1 9.7 7.4 9.2 8.3 8.5 6.8 7.5 7.2 9.2 8.1 7.3 7.7 8.1 21 22 23 24 25 26 BRATED PRO 8.8 10.2