In Problem 13.4, the percentage of .mm alcohol was used to predict wine quality (stored in Vinho Verde) For those data, SSR = 21.8677 and SST = 64.0000.
a. Determine the coefficient of determination, r², and interpret its meaning.
b. Determine the standard error of the estimate.
c. How useful do you think this regression model is for predicting sales?

Problem 13.4

The production of wine is a multibillion-dollar worldwide industry. In an attempt to develop a model of wine quality as judged by wine experts, data were collected from red wine variants of Portuguese "Vinho Verde" wine. A sample of 50 wines is stored in Vinho Verde. Develop a simple linear regression model to predict wine quality, measured on a scale from 0 (very bad) to 10 (excellent), based on alcohol content (%).

a. Construct a scatter plot. For these data, b₀ = -0.3529 and b₁ = 0.5624.

b. Interpret the meaning of the slope, b₁, in this problem.

c. Predict the mean wine quality for wines with a 10% alcohol content.

d. What conclusion can you reach based on the results of (a)-(c)?