Question

amber created a scatter plot and drew a line of best fit, as shown. what is the equation of the line of best fit that amber drew? a. y = 3x + 12 b. y = 3x + 15 c. y = ⅓x + 12 d. y = ⅓x + 15

Explanation:

Step1: Recall slope - intercept form

The equation of a line is $y = mx + b$, where $m$ is the slope and $b$ is the y - intercept.

Step2: Estimate y - intercept

The line crosses the y - axis around $y = 12$, so $b\approx12$.

Step3: Estimate slope

Pick two points on the line, say $(0,12)$ and $(6,14)$. The slope $m=\frac{y_2 - y_1}{x_2 - x_1}=\frac{14 - 12}{6-0}=\frac{2}{6}=\frac{1}{3}$.

Answer:

C. $y=\frac{1}{3}x + 12$