Question

This table shows the relationship between the diameter of a tire and its cost a Kim’s discount hubcapsWhat is the best prediction of the cost of hubcap with a diameter of 20 inches

Answer 1

Answer:

Concept:

We will have to get the formula connecting the diameter and the cost

Step 1:

We will bring put two coordinates below as

$\begin{gathered} (x_1,y_1)\Rightarrow(14,40) \\ (x_2,y_2)\Rightarrow(16,50) \end{gathered}$

To figure out the equation of the line, we will use the formula below

$\frac{y_2-y_1}{x_2-x_1}=\frac{y-y_1}{x-x_1}$

By substituting the values, we will have

$\begin{gathered} \frac{y_{2}-y_{1}}{x_{2}-x_{1}}=\frac{y-y_{1}}{x-x_{1}} \\ \frac{50-40}{16-14}=\frac{y-40}{x-14} \\ \frac{10}{2}=\frac{y-40}{x-14} \\ y-40=5(x-14) \\ y-40=5x-70 \\ y=5x-70+40 \\ y=5x-30 \end{gathered}$

Step 2:

To get the cost of a hubcap with a diameter of 20 inches , we will substitute x=20 in the equation below

$\begin{gathered} y=5x-30 \\ y=5(20)-30 \\ y=100-30 \\ y=70 \end{gathered}$

Hence,

The final asnwer is

$\Rightarrow70$

The FIRST OPTION is the right answer