A business statistics professor at State College would like to develop a regression model to predict the final exam scores for students based on their current grade point averages (GPAs), the number of hours they studied for the exam, and the number of times they were absent during the semester. The data for these variables can be found in the Excel file final exam scores 1.xlsx.
a. Construct a regression model using all three independent variables.
b. Interpret the meaning of the regression coefficients.
c. Predict the average exam score for a student who studied 4.0 hours for the exam, missed two classes during the semester, and has a current GPA of 2.95.
d. Construct a 90% confidence interval for the average exam score for a student who studied 3.0 hours, missed four classes, and has a GPA equal to 3.10.
e. Construct a 90% prediction interval for the exam score for a particular student who studied 3.0 hours, missed four classes, and has a GPA equal to 3.10.
f. Explain the reason for the different intervals in parts d and e.