Question

Analyzing Slope
On a coordinate plane, a line goes through points (4, 24) and (16, 18).

Willa says the slope of the graph is Negative one-third. What error did she make when finding the slope?
The slope is positive instead of negative.
She counted the squares instead of using the scale.
She used the points that are further apart instead of the two consecutive points.
She used StartFraction rise Over run EndFraction when finding slope.

Answer 1

Answer: She counted the squares instead of using the scale.

Work: slope = (18 − 24)/(16 − 4) = −6/12 = −1/2. Willa’s −1/3 likely came from counting grid squares rather than using the coordinate scale, so she mis-measured the rise/run.