Question

Choose the equation below which would be the line of best fit for the scatterplot. Is the correct answer a, B, C, or D?

Answer 1

To find the line of best fit for the scatterplot, we pick points from the graph as shown below

From the graph,

`\begin{gathered} (x_1,y_1)\Rightarrow(2,8) \\ (x_2,y_2)\Rightarrow(1,9) \end{gathered}`

To find the equation of a straight line, the formula is

`(y-y_1)/(x-x_1)=(y_2-y_1)/(x_2-x_1)`

Substitute the coordinates into the formula above

`\begin{gathered} (y-8)/(x-2)=(9-8)/(1-2) \\ (y-8)/(x-2)=(1)/(-1) \\ (y-8)/(x-2)=(-1)/(1) \\ Crossmultiply \\ 1(y-8)=-1(x-2) \\ y-8=-x+2 \\ y=-x+2+8 \\ y=-x+10 \end{gathered}`

Hence, the line of best fit is

`y=-x+10`