Question

Which equation is the BEST fit for the data in the graph?

A) y = x + 2

B) y = 2x + 1

C) y = x - 1/2

D) y = 1/2x - 1

Answer 1

B.y = 2x + 1.

Explanation:

By first sketching a line of best fit then comparing it to the given equations, the equation that best matches the graph is y = 2x + 1.

Answer 2

Use a straight edge to approximate the y-intercept. It turns out to be (0,0). Next, choose a point at the other end of the graph. One such point might be (9.5, 19.5).

Thus, the slope of this regression line is m = rise / run = 19.5 / 9.5 = 2.05.

I would say that the best fit based upon these calculations would be

y = 2x + 0.

Choice B is not exactly the same: y = 2x + 1.

However, Choice B is closest to the calculated y = 2x + 0.