Answer:
Step-by-step explanation:
x y xy x^2 y^2
7.1 7.1 50.41 50.41 50.41
6.2 6.2 38.44 38.44 38.44
10.3 10.3 106.09 106.09 106.09
4.5 4.5 20.25 20.25 20.25
9.7 9.7 94.09 94.09 94.09
8.3 8.3 68.89 68.89 68.89
7 7 49 49 49
6.4 5.5 35.2 40.96 30.25
Mean 7.4375 7.325 57.79625 58.51625 57.1775
Cov 3.3165625 r #DIV/0!
r 0.987954244
r^2 0.976053588
The coefficient of determination r square is 97.60%
Hence 97.6% variation is explained by changes in grade level
Nearest answer is option b