Costco sells paperback books in their retail stores and wants to examine the relationship between the prices and sales. The price of a particular novel was adjusted each week and the weekly sales are in the following table. Management would like to use a simple linear regression model that uses prices to predict sales.

Sales Price

7 $12

4 $11

5 $10

9 $9

8 $8

8 $7

7 $7

The regression sum of squares for this sample is equal to ________.

A. 4.17

B. 4.61

C. 5.16

D. 6.25