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. (a)What is Keith's unit rate of change of dollars with respect to time; that is, how much does Keith save in one year? The unit rate is dollars per year. (b)Graph the proportional relationship described above, with the x-coordinate representing years, and the y- coordinate representing amount saved in thousands of dollars.

Answer 1

Answer:

(a)$1500 per year.

Explanation:

(a)From the table:

3000-1500=$1500

4500-3000=$1500

This means that every year, Keith adds $1500 to his savings.

The unit rate is $1500 per year.

(b)

If x=number of years; and

y=Amount saved (in thousands of dollars.​)

When x=1, y=$1.5

When x=2, y=$3.0=2x1.5

When x=3, y=$4.5=3x1.5

The equation of proportion is therefore:

$y=1.5x$

When x=0, y=0 (0,0)

When x=1, y=1.5 (1, 1.5)

We join the points (0,0) and (1,1.5)

The graph of the proportional relationship is attached below.