Question

Your grandmother deposited some money on your saving account several years ago. If after 4 years, you had $489 and after 6 years, you had $567 on your account. How much did your grandmother deposit originally? Use the first point to find the original value.

Round your answer to two decimal places.

Answer 1

12.45

Explanation:

12.45-3

Answer 2

$372

Explanation:

If after 4 years, you had $489 and after 6 years, you had $567 on your account.

We first determine the slope of the points (4,489) and (6,567).

`Slope, m=(y_2-y_1)/(x_2-x_1) \\=(567-489)/(6-2) \\=39`

Using the slope-Intercept form, y=mx+c and the first value $489

y=mx+c

489=39(4)+c

c=489-156=333

The equation of the line is:

y=39x+333

The Initial Deposit,y at x=1

y=39(1)+333

Initial Deposit =$372