CORELATION AND REGRESSION
All questions are from the class data sheet.
1) Create a Pearson's (r) correlation coefficient using the computational formula from Chapter 14 (top of page 456). Correlate GPA with the number of hours spent watching TV, leaving out the data from subject 30. Show your work for all steps: how you get SP, how you get SSx, how you get SSy, and how you get r.
2) Using the r value you got in problem 1), run a statistical inference test for r, with an alpha level of .05. Indicate what the df is, what the appropriate critical value is from the r table (page 581), what the null and alternative hypotheses are, and what the decision is regarding the null and alternative hypotheses.
3) Using the GPA data (Y variable) and the Internet use data (X variable) from the class data sheet, find the 'b' and 'a' parts to the best-fitting regression line, using the formulas on pages 485-486. Then use the formula for the straight line to find the specific GPA (that) that would be predicted by 40 hours of internet use per week. Show your work.
4) Using the F-ratio formula on page 494, test the significance of the regression equation you developed for problem 3), at a .05 alpha level. Indicate the null and alternative hypotheses, the dfs, the critical F ratio number from the F table, and the decision regarding thp null and alternative hypotheses. Show your work.