A team of anthropologists and nutrition experts investigated the influence of protein content in diet on the relationship between AGE and height (HT) for New Guinean children. The first two accompanying tables display values of HT (in centimeters) and AGE for a hypothetical sample of children with protein-rich and protein-poor diets, respectively.
a.-d. Repeat parts (a) through (d) of Problem 1 for the straight-line regressions of HT (Y) on AGE (X) for the two diets. (Consider a two-sided alternative in each case.)
e. Test whether the population correlation coefficient for children with a protein-rich diet differs significantly from that for children with a protein-poor diet. (Consider a two-sided alternative.)
Protein-Rich Diet

Protein-Poor Diet

Summary of Separate Straight-line Fits