The following data are x 5 average on five quizzes before the midterm exam and y 5 score on the midterm exam for n 5 11 students randomly selected from a multiple-section statistics class of about 950 students:

a. Plot the data, and describe the important features of this plot.

b. Using statistical software, calculate the regression line for this sample.

c. What is the predicted midterm exam score for a student with a quiz average equal to 75?

d. With statistical software, determine a 50% prediction interval for the midterm exam score of a student whose quiz average was 75.