Need help figuring out the cost of common stock for retained earnings with the attached information: Please show in excel format as it is required for assignment

Calculation of individual costs and WACC
A.	Par Value of Bond	1000
	Annual Coupon Rate	7%
	Years until Maturity	19
	Current Price	1,025.00
	Flotation Cost	2.00%
	Current Net Price	1,004.50
	Yield to Maturity	7%
	Tax Rate	0.24
	After tax cost of Debt	5.29%
B.	Par Value of Preferred Stock	100.00
	Dividend Rate	7.5%
	Dividend amount	7.5
	Current Price	90.00
	Fee to Underwriters	2.00
	Net Price	88.00
	Cost of Preferred Stock	8.52%
C.	Cost of Retained Earnings	????
	Dividend Paid 10 years ago	2.25
	Last Dividend Paid	4.22
	Dividend Growth Rate	6.49%
	Current Market Price	50.00
	Discount	3.00
	Flotation Cost	2.50
	Net Price	$44.50
	Cost of New Common Stock	16.59%
D.
	Cost of Retained Earnings	?????
	Capital	Weight	Cost
	Debt	50.0%	5.29%
	Preferred Stock	15.0%	8.52%
	Common Stock	35.0%	16.59%
	WACC for Dillion labs	9.73%