An educational designer is studying the relationship between student performance and the provision of online learning content. She collects data on student grades and total time spent viewing online lecture content.

a. Use the least-squares method to calculate the regression coefficients, b0 and b1.

b. Interpret the meaning of the model parameters.

c. Predict the grades of a student who views 100 minutes of online content.

d. Is it appropriate to use the model to predict the marks for students viewing 500 minutes of content?
Explain.

e. Calculate the coefficient of determination, r 2 , and explain its meaning in this problem.

f. Plot the residuals against time online. Is there any evidence of a pattern in the residuals? Explain.
g. Based on the results of (f), is there reason to question the validity of the model? Explain.
h. At the 0.05 level of significance, is there evidence of a linear relationship between student grades and online viewing?
i. Construct a 95% confidence interval estimate of the mean grade for a student with 85 minutes of online vewing.
j. Construct a 95% prediction interval of the grade for a student with 85 minutes of online viewing.
k. Construct a 95% confidence interval estimate of the population slope.