The paper "Correlations Between the Intrauterine Metabolic Environment and Blood Pressure in Adolescent Offspring of Diabetic Mothers" (Journal of Pediatrics, Vol. 136, Issue 5, pp. 587-592) by N. Cho et al. presented findings of research on children of diabetic mothers. Past studies have shown that maternal diabetes results in obesity, blood pressure, and glucose-tolerance complications in the offspring.
The WeissStats CD provides data on systolic blood pressure, in mm Hg, from independent random samples of 99 adolescent offspring of diabetic mothers (ODM) and 80 adolescent offspring of nondiabetic mothers (ONM).
a. Obtain normal probability plots, boxplots, and the standard deviations for the two samples.
b. At the 5% significance level, do the data provide sufficient evidence to conclude that the mean systolic blood pressure of ODM children exceeds that of ONM children?
c. Determine a 95% confidence interval for the difference between the mean systolic blood pressures of ODM and ONM children.
d. Are your procedures in parts (b) and (c) justified? Explain your answer.