For the girls only, draw the scatterplot matrix of HT2, HT9, WT2, WT9, ST9, and BMI18. Write a summary of the information in this scatterplot matrix. Also obtain the matrix of sample correlations...

For the girls only, draw the scatterplot matrix of HT2, HT9, WT2, WT9, ST9, and BMI18. Write a summary of the information in this scatterplot matrix. Also obtain the matrix of sample correlations between the these same variables and compare with the scatterplot matrix.

The following questions all refer to the mean function

Suppose we fit (3.28) to data for which x₁
= 2.2x2, with no error. For example, x₁
could be a weight in pounds, and x₂
the weight of the same object in kilogram. Describe the appearance of the added variable plot for X₂
after X₁.