Continue your work from exercise 1.44 (page 37) with the data file Large.FEV.

(a) How is lung capacity affected by children's growth? Plot the relationship between FEV and age for all the individuals in the data set, using FEV as the response variable. Describe the relationship. Do the same for the relationship between FEV and height.

(b) Display the relationships in (a) separately for boys and for girls (on separate graphs or on the same graph using different symbols). How do boys and girls differ in lung capacity as they age and grow?

(c) Let's examine the impact of smoking on lung capacity for children in middle and high school (ages 11 and up). Display the relationships in (a) separately for smokers and nonsmokers for children aged 11 and up. How does smoking affect the change of lung capacity as children grow and age?