8. [15] An investor makes deposits and withdrawals into a fund. The following table shows all the deposits, withdrawals and the value of the fund at the end of the year. Table 3 Year 0 Deposits Withdrawals Balance 2000 1000 3200 500 2800 300 3200 400 2900 2 3 4 (a) [10] Find the dollar-weighted rate of interest using both compound interest and simple interest. (b) [5] Find the time-weighted rate of interest (compound interest)