You want to determine if the mean score on a standardized math test is different among three groups of schoolchildren ranging in age from 12 to 18. Although the test covers only simple math topics...

You want to determine if the mean score on a standardized math test is different among three groups of schoolchildren ranging in age from 12 to 18. Although the test covers only simple math topics easily understood by a 12-year-old, you want to perform the analysis with and without an adjustment based on age.

(a) Using the following sample data, first perform a one-way ANOVA comparing the math scores and ages among the three groups.

(b) Test if the relationship between age and math score is homogeneous among the three groups.

(c) If the test i.n part B permits, perform an analysis of covariance, comparing the math scores among the three groups, adjusted for age.