Find the principal of interest!! random answers will be reported 1. Interest: $640
Rate: 4%
Time: 1 year
2. Interest: $2,016
Rate: 12%
Time: 3 years

4: $16,000

5: $4978.66

6: .086278 or 8.62%

Step-by-step explanation:

For the entirety of this problem I am going to assume that the interest is compounding annually

4: to find the interest earned in a period you have the following equation

(principle*(1+i)^n)-Principle

We can plug in the values we know

principle=p

(p*1.04)-p=640

This means that p=640/.04

p=16000

5: This is the same deal as the other one

2016=(p*(1.12)^3)-p

Solve this and get 1.404928p-p=2016

This means that .404928p=2016

Which means that p=4978.66

6: This one is slightly different but we can still use the same formula

720=4000((1+i)^2)-4000

We can add 4000 and then divide by 4000 to get

1.18=(1+i)^2

Take the square root of both sides and subtract 1 to solve for i

i= .086278 or 8.62%

cant open file sorry!

step-by-step explanation: