Question

A scatter plot was constructed and a line of best fit drawn as shown.

What is the equation of this best line of fit?

y = 5x + 5
y = x + 5
y = 5x +25
y = x + 125

Answer 1

y = 5x +25

Explanation:

Answer 2

y = 5x +25

Explanation

To get the equation of a line, first get the slope of the line.

Slope = (change in y)/(change in x)

= (60-30)/(7-1)

= 30/6

= 5

Now use one point in the line (4,45) and a general point (x,y).

Slope = (change in y)/(change in x)

5 = (y - 45)/(x - 4)

5(x - 4) = (y - 45)

5x - 20 = y - 45

y = 5x -20 + 45

y = 5x + 25