Based on data on 2,679 high school basketball players, the following model was fitted: y = b0

Question:

Based on data on 2,679 high school basketball players, the following model was fitted:
y = b0 + b1x1 + b2x2 + g + b9x9 + e
where
y = minutes played in season
x1 = field@goal percentage
x2 = free@throw percentage
x3 = rebounds per minute
x4 = points per minute
x5 = fouls per minute
x6 = steals per minute
x7 = blocked shots per minute
x8 = turnovers per minute
x9 = assists per minute
The least squares parameter estimates (with standard
errors in parentheses) were as follows:

The coefficient of determination was as follows:
R2 = 0.5239
a. Find and interpret a 90% confidence interval for Î²6.
b. Find and interpret a 99% confidence interval for Î²7.
c. Test, against the alternative that it is negative, the null hypothesis that Î²8 is 0. Interpret your result.
d. Test, against the alternative that it is positive, the null hypothesis that Î²9 is 0. Interpret your result.
e. Interpret the coefficient of determination.
f. Find and interpret the coefficient of multiple correlation.