In testing for carbon monoxide in a certain brand of cigarette, the data, in milligrams per cigarette, were coded by subtracting 12 from each observation. Use the results of Exercise 8.14 to find the standard deviation for the carbon monoxide contents of a random sample of 15 cigarettes of this brand if the coded measurements are 3.8, —0.9. 5.4, 4.5, 5.2, 5.6, 2.7, - 0.1, -0.3, -1.7, 5.7, 3.3, 4.4, -0.5, and 1.9