Radon levels in a house vary from week to week. In one house a sample of 8 weeks had the following readings for radon level ( in pCi/L): 1.9, 2.8, 5.7, 4.2, 1.9, 8.6, 3.9, 7.2
a) Find the mean, median, and mode
b) Find the sample standard deviation, coefficient variation, and range.