The following table shows, for eight vintages of select wine, purchases per buyer (y) and the wine buyer's rating in a year (x):
X 3.6 3.3 2.8 2.6 2.7 2.9 2.0 2.6
Y 24 21 22 22 18 13 9 6
A. Estimate the regression of purchases per buyer on the buyer's rating.
B. Interpret the slope of the estimated regression line.
C. Find and interpret the coefficient of determination.
D. Find and interpret a 90% confidence interval for the slope of the population regression line.
E. Find a 90% confidence interval for expected purchases per buyer for a vintage for which the buyer's rating is 2.0.