Question

Mia's work to find the slope of a trend line through the points (3, 10) and (35, 91) is shown below:

Mia's Work:
m = (3 - 35) / (10 - 91)
m = (-32) / (-81)
m = 32 / 81

Question:
What was the first error that Mia made?

a) Mia simplified incorrectly and made the slope positive.
b) Mia subtracted in the wrong order.
c) Mia switched the numerator and the denominator.
d) Mia used subtraction instead of addition.

Answer 1

Mia's first error was that she subtracted the coordinates in the wrong order, leading to an incorrect calculation of the slope.

Step-by-step explanation:

Mia's initial error in finding the slope of the trend line between the points (3, 10) and (35, 91) was that she subtracted in the wrong order when applying the slope formula.

To find the slope (m), we use the formula m = (y2 - y1) / (x2 - x1), where (x1, y1) and (x2, y2) are the coordinates of the two points. In Mia's work, she should have calculated the slope as follows:

m = (91 - 10) / (35 - 3)

This would give:

m = 81 / 32

Mia incorrectly reversed the order of subtraction, which should have been the change in y-values over the change in x-values, also referred to as the rise over run.