Answer:
a) total return = ($1,000 x 4.2%) + ($950 - $900) = $92
b) nominal rate of return = total return / total investment = $92 / $900 = 10.22%
c) we calculate the approximate real rate of return = nominal rate of return - inflation rate = 10.22% - 2.5% = 7.72%
if we want to determine the exact real rate of return:
exact real rate of return = [(1 + nominal rate) / (1 + inflation rate)] - 1 = (1.1022 /1.025) - 1 = 7.53%