Data from 75 students in three undergraduate classes have been collected.The data includes the amount of time to complete the test (duration) and the student's score on the test. Assuming I wish to complete a model to predict a student's test score based on the amount of time to complete the test, complete a least-squares linear regression (using excel or tool of your choice) and answer the following questions:

1) Treating the 75 students as a single dataset, what is the regression equation? (use the form y = a + bx, what is the Y variable, what are the a, b, and x values)

2) What percentage of the grade variance is explained by duration or time taken to complete the exam (e.g., percentage of variance explained by the regression line)? HINT: What information is provided by r2, or coefficient of determination?

3) Is the R-squared value significantly different from zero (e.g, does thelinear regression model provide a better fit to the data than a model that contains no independent variables)? HINT: What information is provided by the F-statistic?

Duration Duration Duration order score order score (minutes) order score (minutes) (minutes) 92 20 15 15 92 86 74 21 96 16 76 W N 17 80 22 W N 17 58 84 23 80 86 18 17 24 70 5 19 78 18 90 82 6 20 76 25 19 94 84 26 76 21 20 84 22 82 27 70 20 72 66 28 88 21 96 23 10 29 76 22 82 10 24 96 10 25 80 11 30 94 11 23 86 11 80 26 96 12 31 12 23 86 12 32 13 27 84 13 24 80 13 86 14 33 90 14 25 74 14 28 15 34 74 15 26 76 15 29 74 90 16 35 90 16 26 84 16 30 78 17 36 68 31 17 27 17 37 78 18 32 86 18 18 28 92 19 38 76 90 19 84 33 29 19 39 88 34 84 20 20 29 84 20 21 40 68 30 84 21 35 72 21 82 22 41 86 96 22 36 22 31 94 23 37 82 23 32 24 32 64 25 33 82 26 34 74 27 35 80 28 35 80 29 36 88 30 37 52