
Ryan S. answered 09/24/13
Tutor
4.8
(10)
Mathematics and Statistics
Your question is using the term "return" in an unusual way. Usually return refers to rate of return which in this case is the interest rate. For this problem, I will interpret return as the dollars earned as interest.
Also the formula you have for continuous compounding is not correct. A=P*e^(i*t) where A = Account value, P = initial balance, i = interest per year, and t = time in years. The symbol ^ means raised to the power of.
Let A(t) be the account value at time t in years.
Let r(t) = A(t)-3000
Annual compounding
A(6) = $3000*1.07^6=$4502.19
r(t) = $1502.19
Monthly compounding
A(6) = $3000*(1+.07/12)^(6*12) = $4560.32
r(t) = $1560.32
Continuous compounding
A(6) = $3000*e^(.07*6) =$4565.88
r(t) = $1565.88