20. A survey was created to assess the number of hours students work per week (X) and their exam grade on a 30-point test (Y). The researchers research hypothesis suggested that number of hours worked per week will be correlated with exam grades, The researchers collected the following data from 10 students, Use this data to answer a-n. Remember to triple check your math and round to the thousandths place! Student Hours Exam X2 Y2 XY Worked Grades (X (Y) 30 14 7 25 4 27 26 12 D JOUAWN- 18 16 15 22 6 28 12 20 3 29 10 8 26 n = 10 EX= CY= EX2 EXY= a. Plot the data on a scatterplot. (1 points) c. Compute the degrees of freedom (df). (1 point) d. From Table R, what is the critical value for a two-tailed test at the 0.05 level? (1 point) e. Is the correlation coefficient significant? (1 point) Yes or No f. Should you fail to reject the null or reject the null hypothesis? (1 point) Fail to reject the null or Reject the null g. Write the correlation coefficient results in APA format. (2 points) h. What percentage of variability in student's exam grades can be explained by the number of hours spent working per week? (1 point) i. What percentage of variability in student's exam grades is unexplained by the number of hours spent working per week? (1 point) j. Calculate the regression coefficients (a and b) for predicting exam grades (Y)- show all your work and remember to round all work to the thousandths place. (3 points)