Forced expiratory volume (FEV) measures how much air a person can exhale during a forced breath. Variables in our data set include Sex (1 male, 0 female); fev, forced expiratory volume in liters, and Smoke, an indicator of smoking status (1 current smoker, 0 noncurrent smoker) on 654 patients aged 3 to 19. You can read this data set into Stata using the command use http://people.fas.harvard.edu/~mparzen/stat104/fev a) Tabulate Sex. What are the frequencies and relative frequencies of boys and girls in this data set? [Stata command tabulate Sex] b) Describe the distribution of Age for these children. Be sure to include at least one measure of central tendency, one measure of dispersion, and one graph. Is the distribution of age symmetric or skewed? Explain. c) Using box plots to display the data graphically, does fev appear to differ by Sex? [Stata command graph box fev,by(Sex)] d) Tabulate smoking status (Smoke) by Sex. Does smoking appear to differ between boys and girls? Stata Commands to do this: sort Sex by Sex: tabulate Smoke e) Using a scatter plot, describe the relationship between FEV and age.