Question

The scatter plot below shows the ages and lengths of 20 rattlesnakes.

A scatter plot is shown with 20 data points showing a strong positive relationship. The x-values of the data points extend from 0 to 10, and the y-values of the data points extend from 10 to 16. First data point is approximately at (0, 10) and the last data point is approximately at (10, 16).

According to the data in this plot, which expression gives the best prediction for the length (in inches) of a rattlesnake that is 8 months old?

A.
6
(
8
)
+
10

B.
0
.
6
(
8
)
+
10

C.
10
(
8
)
+
0
.
6

D.
10
(
8
)
+
6

Answer 1

When x = 0 the length is 10 and when x = 10 the length is 16, so slope = (16 − 10)/(10 − 0) = 0.6. The line is y = 0.6x + 10, so for x = 8: y = 0.6(8) + 10 = 14.8.

Answer: B.