Secondhand Smoke The cotinine measurements of nonsmokers who were exposed to tobacco smoke at home or work, as listed in Data Set 9 in the Appendix: Data Sets. Determining Normality. In Exercises 9–12, refer to the indicated sample data and determine whether they appear to be from a population with a normal distribution.

Assume that this requirement is loose in the sense that the population distribution need not be exactly normal, but it must be a distribution that is roughly bell-shaped.