Chapter 11.2, Problem 64E

Preliminary data analyses and other information indicate that you can reasonably assume that, in Exercises 11.63–11.68, the variable under consideration is normally distributed on both populations. For each exercise, use either the critical-value approach or the P-value approach to perform the required hypothesis test.

11.64 Pulmonary Hypertension. In the paper “Persistent Pulmonary Hypertension of the Neonate and Asymmetric Growth Restriction” (Obstetrics & Gynecology, Vol. 91, No. 3, pp. 336–341), M. Williams et al. reported on a study of characteristics of neonates. Infants treated for pulmonary hypertension, called the PH group, were compared with those not so treated, called the control group. One of the characteristics measured was head circumference. The following data, in centimeters (cm), are based on the results obtained by the researchers.

Do the data provide sufficient evidence to conclude that variation in head circumference differs among neonates treated for pulmonary hypertension and those not so treated? Perform an F-test at the 5% significance level. (Note: s₁, = 1.907 and s₂ = 1.594.)