3. The table shows the test scores and the sleep averages of several students.

Test Score (%) 88 75 76 92 96 94 83 90 99 65 77 88 82 83 94 97
Average Sleep (h) 7 6.5 6 7.5 8 7 6.5 8 8.5 5 7 9 8 8.5 8.5 9

(a) Write the least squares regression equation that models the data.
Let x = the test score and y = average sleep.
(b) Use the equation to determine the approximate test score of a student who sleeps an average of 8 hours a night.
Show your work.