Question

Do A-D

The following table contains the ACT scores and the GPA (grade point average) for eight college students. Grade point average is based on a four-point scale and has been rounded to one digit after the decimal.

Student 1 2 3 4 5 6 7 8

GPA (y) 2.8 3.4 3.0 3.5 3.6 3.0 2.7 3.7

ACT (x) 21 24 26 27 29 25 25 30

We want to fit a straight-line model to relate GPA y to the ACT. ??? = ?0 + ?1 ??? + ?

a. Compute: ????, ????, ????, ?̂ 0, ?̂ 1 and hence write the equation of the fitted line.

b. Compute the fitted values and residuals for each observation, and verify that the residuals (approximately) sum to zero. (Do not use computer for parts c,d,e).

c. Draw a scatter plot of ACT and GPA

d. On your scatter plot draw the fitted line you have in part (b).

e. On your plot indicate ?3, ?̂3,?̂3

Where ?̂3 ?? ?ℎ? ???????? ??? ?ℎ? ?ℎ??? ???????????.

Answer 1