Question

Andrea’s work to find the equation of a trend line through the points (48, 61) and (72, 195) is shown below

Answer 1

The reasonable question of this incomplete problem is to find the equation for the trendline out of the given two points. Hence, we use the two-point formula of a line.

y - y₁ = [(y₂ - y₁)/(x₂- x₁)]*(x - x₁)

Let (48,61) be point 1, and (72,195) be point 2. Then,

y - 61 = [(195 - 61)/(72- 48)]*(x - 48)
y - 61 = (67/12)(x - 48)
12y - 732 = 67(x - 48)
12y - 732 = 67x - 3216
12y - 67x - 732 + 3216 = 0
12y - 67x +2484 = 0

Thus, the equation for the trendline is 12y - 67x +2484 = 0.

Answer 2

A - Andrea used the reciprocal of the slope