Using the information given here, answer the same questions as in Problem 11 about the regression of height (Y) on age (X) for children in one of two diet categories. (This problem is based on the data in Problem 3.)
In Problem 11
a. State the regression model that incorporates the straight-line models for each group of countries.
b. Determine and plot the separate fitted straight lines, based on the fitted regression model given in part (a).
c. Test for parallelism of the two straight lines.
d. Test for coincidence of the two straight lines.
e. Compare your results in parts (b) through (d) to those obtained in Problem 2.
Regression of HEIGHT on AGE, Z, and AGE × Z
Where Z = 1 if Protein Rich, 0 Otherwise