Nonsmokers: 15.2,16.4,12.8,21,19.8,9.8,12.5 15.4,18.5,9.4,17.1,22.5,25.5,9.8,7.5 17.8,12.2,15, Smokers: 22,27.1,15,24.1,30.5,17.8,20.8 27.8,23.4,22.5,24.5,20.4,12.5,20.4, Compare the distribution cadmium levels for smokers and nonsmokers using stem-and-leaf display. Describe cadmium levels for the two groups relative to symmetry and skewness..