Question

Keith is saving money for a car. He has saved the same amount each year for the past three years, and records how much he has at the end of each year in the table below.
Year 1: 1500 year 2: 3000 year 3: 4500


What is Keith's unit rate of change of dollars with respect to time; that is, how much does Keith save in one year?

Answer 1

Answer:

Keith's unit rate of change of dollars with respect to time is $1500.

Step-by-step explanation:

It is given that Keith is saving money for a car.

Year 1: 1500

year 2: 3000

year 3: 4500

Let y be the saved amount after x year.

The coordinate pairs according to the given table are (1,1500), (2,3000) and (3,4500).

The formula for rate of change is

$m=\frac{y_2-y_1}{x_2-x_1}$

Consider any two coordinate pairs.

Let as consider (1,1500) and (2,3000). So, Keith's unit rate of change of dollars with respect to time is

$m=\frac{3000-1500}{2-1}$

$m=\frac{1500}{1}$

$m=1500$

Therefore, Keith's unit rate of change of dollars with respect to time is $1500.

Answer 2

So, if he ends up with 1500 at the end of a year then he save up 1500 per year