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 was collected from red wine variants of Portuguese “ Vinho Verde” wine. (Data ­extracted from P. Cortez, Cerdeira, A., Almeida, F., Matos, T., and Reis, J., “ Modeling Wine Preferences by Data Mining from Physiochemical Properties,” Decision Support Systems, 47, 2009, pp. 547– 553 and bit. ly/ 9xKlEa.) A sample of 50 wines is stored in VinhoVerde . 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)?