Blue Sky Corporation has a capital structure of 40% debt and 60% common equity. This capital structure is expected not to change. The firm's tax rate is 21%. The firm can issue the following securities to finance capital investments:

Debt: Capital can be raised through bank loans at a pretax cost of 9.3%. Also, bonds can be issued at a pretax cost of 8.1%.

Common Stock: Retained earnings will be available for investment. In addition, new common stock can be issued at the market price of $72. Flotation costs will be $4 per share. The recent common stock dividend was $3.91. Dividends are expected to grow at 4% in the future.

What is the firm's cost of external equity?

PLEASE INPUT THE ANSWER IN PERCENT ROUNDING IT TO 2 DECIMALS. DO NOT INCLUDE % SIGN, E.G., INSTEAD OF 9.99% INPUT 9.99