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

Step 1: 3-35/10-91

Step 2: -32/-81

Step 3: 32/81


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

Answer:

C: Mia switched the numerator and the denominator.

Explanation:

just took the test

Answer 2

For this case the first thing you should know is that by definition the slope of the line is given by:
m = (y2-y1) / (x2-x1)
Where we have two ordered pairs:
P1 = (x1, y1)
P2 = (x2, y2)
We observe then that according to the formula, the error of mine was to invert the numerator with the denominator.
Answer:
C: Mia switched the numerator and the denominator.