Births The lengths of stay (days) of newborn babies, as listed in Data Set 3 “Births” in Appendix B. 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.