Delta Corporation has 650,000 shares of common stock outstanding at a market price of $34.7 a share. Last month, Delta paid an annual dividend in the amount of $1.88 per share. The dividend growth rate is 4.5%. Delta also has 31,000 bonds outstanding with a face value of $1,000 per bond. The bonds carry a 6% coupon, pay interest annually, and mature in 20 years. The bonds are selling at 98% of face value. The company's tax rate is 25%. What is Delta's weighted average cost of capital?