I posted this question yesterday but did not get a response so am posting again in hopes that I will get a response today. I am asking for someone to check my answers.

Question

The table shows the cost of renting a full-size rental car, based on the number of miles driven.
Distance Driven in miles Total Cost
0 $68.97
50 $88.47
100 $107.97
150 $127.47
200 $146.97

1)Find the slope of the line and explain what it means.

I did 88.47 - 68.97/50-0 to get $.39 is the slope which means that the cost per mile of renting the car.

(although I'm slightly doubting that because the inital cost is $68.97 for just getting the car??)

Find the y-intercept and explain what it means.

This I am stuck on because I thought the left column in a table was the x axis and the right column was the y axis so I'm not sure how to get this????

Determine the equation of the line. If I use the slope determined above, assuming it is correct, I believe the equation would be 68.97 + .39x
That's an expression, not an equation, but I'm not sure what to make it equal to??

I am trying to decide whether I can afford to rent a full-size car to drive to St. Louis, which is about 180 miles away. How much would that cost for a one-way trip? How much would it cost for a round trip of 360 miles?
If I use the above and plug in 180 for x, I get $139.17 for the entire trip. Multiply that times 2 for the 360 miles and I get $278.34.

Am I anywhere close to getting these answers correct?

Thank you for your help.

Answer 1

y=mx+b is the intercept.

From what you show it should be correct except the round trip. You see, you are including the rental price twice by multiplying it by two. You should actually re-use your equations with 360 miles.

68.97 + .39x
68.97+ .39(360)
$209.37