For the Pygmalion data in Section 11.2.1, use the function reglev to determine which points, if any, are regression outliers. (The data for the control group are stored in pygc.dat, and the data for...

For the Pygmalion data in Section 11.2.1, use the function reglev to determine which points, if any, are regression outliers. (The data for the control group are stored in pygc.dat, and the data for the experimental group are stored in pyge.dat.)

Use runmean to plot a smooth of the Pygmalion data using f = .75 and 20% trimmed means. Create a plot for both the control and experimental groups when the goal is to predict post–IQ scores with pretest scores. Comment on how the results compare to using f = 1.