If the compound interest formula gives you $13,200 and your investment was $11,500, how much interest did you earn?

$1700

Step-by-step explanation:

The compound interest formula gives the total value of the investment after a certain duration considering the rate of interest.

To fins the amount of interest gained, we deduct the initial value of investment from the total compound amount.

Interest=A-P

Where P is principal amount of investment and A is the final value of money.

Substituting $13200 for A and $11500 for P then

I=13200-11500=$1700

Therefore, interest amount is equivalent to $1700

$195  x  40%

195  x .40 = 78

The price decrease is $78.00

Hope this helps. :)