5.80 An investment plan allows investors to deposit a minimum of £1,000 at the beginning of the term, which pays a fixed return rate of 5% per annum. After a year, investors have to deposit a minimum of

£800 with an expected return rate of 3% per annum for the second year and a standard deviation of 2%

per annum.

a. Find the expected value of the total minimum amount earned after two years of investment.

b. Find the standard deviation of the total minimum amount earned after two years of investment.