Question

The following graph shows the price and miles driven for a sample of Ford F-150's. Theequation of the least squares regression line is also given.Help answer all the parts please. My answers are all wrong.

Answer 1

The regression line equation is given as

`^{}y=38.257-0.1629x`

a.

When the truck has driven 100.000 miles, it means x = 100.000

Substitute x = 100.000 into the regression line equation

y = 38.257 - 0.1629(100.000)

y=38.257 - 16290

y= $21967

The price of the truck after driving 100.000 miles is $21967

b.Interprete the slope:

`\begin{gathered} \text{slope = }\frac{change\text{ in y}}{\text{change in x}} \\ \\ \text{that is } \\ \text{slope = }\frac{change\text{ in }price\text{ (\$)}}{\text{change in miles driven(}mi)}\text{ = } \\ \\ \text{The unit of the slope is dollar per mile driven (\$/mi)} \end{gathered}`

This can be interpreted as the the price for driving just 1 mile

Hence, the slope is the price that will cost to drive 1 mile

C. The y-intercept of the line

The y-intercept is where the line x = 0

This means the price of the Ford when mile covered is zero.

The is interpreted as the initial price of the Ford before it begins to cover any mile.