Help needed with part a #3.

Suppose you purchase a ten-year bond with 4% annual coupons. You hold the bond for four years and sell it immediately after receiving the fourth coupon. If the bond's yield to maturity was 2.28% when you purchased and sold the bond,

(Note: Assume annual compounding)

a. What cash flows will you pay and receive from your investment in the bond per $100 face value?

a1. The cash flow at time 1-3 is $4.00

a2. The cash outflow at time 0 is $115.23

a3. The total cash flow at time 4 (after the fourth coupon) is ???

b. What is the internal rate of return on your investment? 3.41%