5.30 Music file size on a tablet PC. A tablet PC contains 3217 music files. The distribution of file size is highly skewed with many small file sizes. Assume that the standard deviation for this population is 3.25 megabytes (MB).
(a) What is the standard deviation of the average file size when you take an SRS of 25 files from this population?
(b) How many files would you need to sample if you wanted the standard deviation of to be no larger than 0.50 MB?