Hello i need help solving the problem attached thank you.

8. Ashley makes a withdrawal of 100 at time t = 1, a deposit of 300 at time t = 2, a withdrawal of 100 at time t = 3 and a deposit of 200 at time t = 4. The bank account credits interest at an annual effective rate of 7%. Greg makes a deposit of 300 at time T. The present value of Ashley's sequence of withdrawals/deposits is equal to the present value of Greg's single deposit at time T. (a) Find the exact value of T. (b) Use the dollar weighted average to approximate T. Call it T. (c) Does it follow that T 2 T in this example? Explain why this does not contradict 2.3.11 on page 83