QUESTION 7 7.1 Calculate the effective interest rate per annum if an investment earns interest at a rate of 11,5% p.a., compounded monthly. 7.2 Karabo bought a computer for R4 700. The value of the computer depreciated at a rate of 18% p.a. Using the reducing-balance method, calculate the book value of the computer 4 years afier it was bought. 7.3 Nhlanhla made an initial deposit of R20 000 into an investment account that paid interest at the rate of 7.2% p.a., compounded quarterly. fter 2 years the interest rate changed to 7,8% p.3., cnmpounded monthly. Four years after his initial deposit, Nhlanhla withdrew R2 500 from his investment. 7.3.1 Calculate how much Nhlanhla had in this investment account 2 years after the initial depost was made. 7.3.2 How m cl w the investment be worth 7 years after the initial deposit