Find the convexity of a seven-year maturity, 6.5% coupon bond selling at a yield to maturity of 8.8%. The bond pays its coupons annually. (Do not round intermediate calculations. Round your answer to 4 decimal places.)

This is my work, and my answer was incorrect. I used excel. Please help me!

	Time	Cash Flow	PV(CF)	t+(t^2)	(t+t^2) * PV(CF)
	1.00	65	59.74264706	2	119.4852941
6.50%	2.00	65	54.91052119	6	329.4631272
8.80%	3.00	65	50.46922904	12	605.6307485
7.00	4.00	65	46.38715904	20	927.7431809
883.46	5.00	65	42.63525647	30	1279.057694
	6.00	65	39.18681661	42	1645.846298
	7.00	1065	590.1295205	56	33047.25315
		SUM	883.4611499		37954.47949
					50.85496671