Exam Data Set 8 contains 50 matched pairs of measurements of the magnitude (Richter Scale) and epicenter depth (in km) randomly selected from among 10,594 earthquakes recorded in one year from a location in southern California. Fit a regression model to predict the depth of the epicenter of an earthquake, using magnitude as the predictor variable (NOTE: save the residuals for future use). Use a significance level of = 0.05 for the correlation hypothesis test. What is the best estimate of the depth of an earthquake's epicenter if its magnitude is 2.1? (