4. Load the housing data set entitled "nbasal.dta" into Stata. This is a dataset of various performance and background indicators from a random sample of NBA players. When submitting your answers, please put both the Stata command and output from this command that was used to answer the question. (a) Separately graph the density of the variables age and points (per game). Describe the distributions using the graph and summary statistics. How do they compare to a normal distribution? (b) Create a new variable that is the natural log of the variable "wage". Calculate the summary statistics for this variable. (c) Test that the mean number of points scored by all NBA players in the population of all houses is 11 at the 10%, 5% and 1% significance level. Carefully write out your null, alternative and indicate your conclusions