In: Finance
Ans A: Cost of elephants 14000 Welma will buy the elephants at this value in three years thus 14000 is our future value of elephants; Rate = 5% p.a. Time = 3 years. to find out how much Welma needs to invest at this moment in time we will find the Present Value using the formula PV= FV / (1+rate)^n = 14000 / (1+0.05)^3 = 12093.73. Thus Welma needs to invest 12093.73 at this moment in time to have enough money in 3 years to buy the elephant.
And B: Elephants cost in 3 years is $16000 we take the Present Value of elephant deduced in the answer A above i.e. 12093.73 to know the real rate of return on T-bills we would first found the rate at which 12093.73 will become 16000 in 3 years. For this we will be using the RATE function in excel i.e. = RATE(nper,,PV,-FV,0) where nper = 3; PV= 12093.73 and FV=16000 after substituting the variables in the formula we would get =RATE(3,,12093.73,-16000,0) = 9.78%. Note this rate is with inflationary effect.
We will find the Rate of inflation by assuming that 14000 is the value of elephant without inflation effect now if it becomes 16000 in 3 years the only reason is the inflation rate. To find the inflation rate we would again use the RATE function in excel i.e. = RATE(nper,,PV,-FV,0) where nper = 3; PV= 14000 and FV=16000 after substituting the variables in the formula we would get =RATE(3,,14000,-16000,0) = 4.55%. Note this rate is inflation rate.
Thus the real rate of return is Nominal Interest Rate = 9.78% less Inflation rate = 4.55% therefore we would get = 9.78 - 4.55 = 5.23%
To answer Jack and Diane question we need more information about equation 5.15 of the book.