Statistical Bulletin (0ct.-Dec. 1999) reported the average hospital charge and the average length of
Hospital stay for patients undergoing radical prostatectomies in a sample of 32 states. The data are listed in the accompanying table.
a. Plot the data on a scattergram.
b. Use the method of least squares to model the relationship between average hospital charge (y) and length of hospital stay (x)
c. Find the estimated standard error of the regression model and interpret its value in the context of the problem
For a hospital stay of length x = 4 days, find 
e. What fraction of the states in the sample have average hospital charges within f 2s of the least squares line?
