Question

The following scatter diagram shows two sets of data, x and y, that show high positive correlation: Which of the following gives the most accurate answer for the equation of the line of best fit?

• A. $y=1.5x+2$
• B. $y=2x+3$
• C. $y=3x+1$
• D. $y=3x+2$

Answer 1

Answer: (D)

$y=3x+2$

From diagram, we can say that at $x=2$ $y$ deviate from other points

At $x=0.5y=3$

$x=4y=13.5$

$(y-3)=\frac{(13.5-3)}{(4-0.5)}(x-0.5)$

$y-3=3x-1.5$

$\therefore y=3x+1.5$

But $x=2,y=3x+1$ gives $y=7$ (more deviations)

$y=3x+2$ gives $y=8$ (less deviations from acheal value)

$\therefore y=3x+2$ is line of best fit.