The following data represent the number of days absent, x, and the final grade, y, for a sample of college students in a general education course at a large state university.

(a) Find the least-squares regression line treating number of absences as the explanatory variable and final grade as the response variable.
(b) Interpret the slope and y-intercept, if appropriate.
(c) Predict the final grade for a student who misses five class periods and compute the residual. Is the final grade above or below average for this number of absences?
(d) Draw the least-squares regression line on the scatter diagram of the data.
(e) Would it be reasonable to use the least-squares regression line to predict the final grade for a student who has missed 15 class periods? Why or why not?

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No. of absences, r 01 2 3 4 5 6 7 8 9 Final grade,y 89.2 86.4 83.5 81.1 78.2 73.9 64.3 71.8 65.5 66.2