Answer
Final grade for statistics students who score an 83 on their midterm and a 92 on their project:
The 95% confidence interval is between 68.9997 and 82.0370
(for the mean final grade of all statistics students who score an 83 on their midterm and a 92 on their project)
The 95% prediction interval is between 64.0372 and 86.9995
(for the final grade of a particular statistics student who scores an 83 on their midterm and a 92 on their project)
Work Step by Step
With the results from item (b) still available in MINITAB:
Select Stats -> Regression -> Regression -> Predict
Enter 83 and 92 in the first row of the table.
Click in Options and enter the level of confidence. Click OK.
Click OK.
