You made an investment of $12,000 into an account that paid you an annual interest rate of 3.5 percent for the first 5 years and 7.9 percent for the next 15 years. what was your annual rate of return over the entire 20 years

interest rate r = 6.78 %

Explanation:

given data

investment = $12,000

interest rate = 3.5 percent = 0.035

time = 5 year

interest rate =  7.9 percent = 0.079

time = next 15 year

to find out

What was your annual rate of return over the entire 20 years

solution

we get here interest rate as

interest rate r =     ...................1

here t1 is time period for first 5 year and t2 is time i.e next 15 year and r1 and r2 is rate

now put here value we get

interest rate r =

interest rate r =

interest rate r = 1.0678 - 1

interest rate r = 0.0678

interest rate r = 6.78 %

i would say a penny hope it you