Question

1. Ernest calculated the slope of the graph during the uphill climb to be 10. His work is shown below. Determine whether his calculation was correct or incorrect, and then

explain why.
(2 points: 1 for the answer, 1 for the explanation)

Points: (60, 900). (15, 450)
900-450/60-15 = 450/45 = 10

Answer 1

• answer is correct
• the correct formula was used appropriately

Explanation:

The slope of a line on a graph is found using the slope formula:

m = (y2 -y1)/(x2 -x1)

Ernest used (x1, y1) = (15, 450) and (x2, y2) = (60, 900) to fill values into this formula. In doing so, he got ...

m = (900 -450)/(60 -15) = 450/45 = 10

This is an appropriate use of the formula, so gave Ernest the correct answer.