Apply Cleveland's method to Canadian wage data from Problem 5. Obtain an estimate using a span found by trial and error. Then obtain estimates using the two cross-validation span selectors. Comment on the graphical comparison between these estimates.
Problem 5
Pagan and Ullah (1999) reported data from the 1971 Canadian census on wages for male high school graduates. This data in the R object cps71. Use the logarithm of wages log wage as the response and age as the predictor. Smooth this data using Friedman's method with the span found by trial and error. Comment on the graphical comparison between this estimate to that obtained when using the span selected by cross-validation.