A class of 63 students has two hourly exams and a final exam. The regression model was constructed to predict the poerfomance on the final exam based on the results of the two hour exams
(x, and x2). The following are some quantities of interest:
0.9129168 -0.00981502 -0.00071092
(x'x)-' -0.00981502 1.497241e-04 -4.15806 - 05
(-0.00071092 -4.158056 - 05 5.81235e - 05
4871.0
(X'y) = 426011.0
367576.5
Assume y'y = {y} = 411, 222.7041.
63
(a) Find a 95% confidence interval for the coefficient of hourly 1 test.
Round your answers to three decimal places (e. g. 98.765).
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(b) Find a 95% confidence interval for the mean final grade for students who score 80 on the first test and 85 on the second.
Round your answers to two decimal places (e. g. 98.76).
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