13.2 Answer the following for the data of Exercise 12.11: a. What is the 10-percentile and 90-percentile from the sample? b. What is the mean number of disk I/O's per program? c. What is the 90% confidence interval for the mean? d. What fraction of programs make less than or equal to 25 I/O's and what is the 90% confidence interval for the fraction? e. What is the one-sided 90% confidence interval for the mean? 12.11 The number of disk I/O's performed by a number of programs were measured as follows: {23, 33, 14, 15, 42, 28, 33, 45, 23, 34, 39, 21, 36, 23, 34, 36, 25, 9, 11, 19, 35, 24, 31, 29, 16, 23, 34, 24, 38, 15, 13, 35, 28). Which index of central tendency would you choose and why