You invest 3400 into account earning simple intrest. The balance is 4624 after 8 years. What is rate of intrest?

2 answers

4624 = 3400(1+i)^8
(1+i)^8 = 1.36 take the 8th root of both sides
1+i = 1.03918
i = .03918 or 3.9%
We use the formula:

M = P( 1 + i )^n

M is the final amount including the principal.

P is the principal amount.

i is the rate of interest per year.

n is the number of years invested.

M = 4624

P = 3400

n = 8 years

We seek i.

4624 = 3400(1 + i)^8

You do the rest.