A researcher performs a survey of a random sample of young people aged 25 to 32. The sample of such people included 340 individuals with four-year college degrees and 260 individuals with high school degrees but no college. (Individuals with community college degrees or no high school degree are excluded here, as are individuals who are not working; you should also exclude them from your analysis.) The results are given in two data files (posted in the Data folder of the Files section of Canvas):

college.txt contains the annual earnings of the 340 individuals with college degrees.

highschool.txt contains the annual earnings of the 260 individuals with high school degrees but no college.

Note: The data is fictitious but realistic. Save this data to your computer and read it into R, e.g. by using scan(file.choose()).

1.(2 points.) Suppose we wish to estimate the PDFs of (i) the earnings of young people with college degrees, and (ii) the earnings of young people with only high school degrees. For each of these populations, draw ONE graph that shows an estimate of the PDF (so two graphs in total. These should be the only graphs you include in your submission.) For each graph, explain in words what it tells you about the shape of the underlying distribution. (You must include these explanations to get credit.)

2.(2 points.) Test the hypothesis that young people with college degrees have the same mean earnings as young people with only high school degrees.