What is the slope for the following table of values? The table represents the total amount spent in a paperback book club after an introductory fee of $12.

# books purchased 1, 2, 3, 4
Cost of book club 21, 30, 39, 48

A. 3
B. 5
C. 7
D. 9

Question

What is the slope for the following table of values?  The table represents the total amount spent in a paperback book club after an introductory fee of $12.

# books purchased  1, 2, 3, 4
Cost of book club  21, 30, 39, 48

	A.	3
	B.	5
	C.	7
	D.	9

directrix · Answer

X: # books purchased  1, 2, 3, 4
Y: Cost of book club  21, 30, 39, 48

Slope = change in y over change in x

(21 - 30)/ (1-2) = -9(-1) = 9

(48 - 39)/ (4-3) = 9/1 = 9

Slope is 9 -->