1.6.11 On January 1 Smith deposits 1000 into an account earning i(4) =.08 with interest credited on the last day of March, June, September, and December. If Smith closes the account during the year, simple interest is paid on the balance from the most recent interest credit date. (a) What is Smith's close-out balance on July 19? (b) Suppose all four quarters in the year are considered equal, and time is measured in years. Derive expressions for Smith's accumulated amount function At), the close-out balance at time t. Consider separately the four intervals 0