On rural highways, the average speed S (in miles per hour) is related to the amount of curvature C (in degrees) of the road. Suppose that on a straight road (C = 0), the average speed is 47.5 miles per hour and that this decreases by 0.65 mph for each additional degree of curvature. What is the average speed if the curvature is 15 degrees?
A)42.35 mph
B)37.75 mph
C)57.15 mph
D)38.35 mph

Question

Quizplus · Accepted Answer

We can use a linear equation to model the relationship between S and C:
S = 47.5 - 0.65C
Plugging in C = 15, we get:
S = 47.5 - 0.65(15) = 37.75
Therefore, the average speed when the curvature is 15 degrees is 37.75 mph, which corresponds to choice B.

On Rural Highways, the Average Speed S (In Miles Per