2.108 Price and ounces. In Example 2.2 (page 80) and Exercise 2.3 (page 82), we examined the relationship between the price and the size of a Mocha Frappuccino^®. The 12-ounce Tall drink costs $3.95, the 16-ounce Grande is $4.45, and the 24-ounce Venti is $4.95.

1. (a) Plot the data and describe the relationship. (Explain why you should plot size in ounces on the x axis.)

2. (b) Find the least-squares regression line for predicting the price using size. Add the line to your plot.

3. (c) Draw a vertical line from the least-squares line to each data point. This gives a graphical picture of the residuals.

4. (d) Find the residuals and verify that they sum to zero.

5. (e) Plot the residuals versus size. Interpret this plot.