Aphid Corpwill finance its next major expansion with 20% debt, 30% preferred stock, and 50% retained earnings. Aphids after-tax cost of debt is 4.3%, cost of peferred stock is 8.9%, and cost if retained earnings is 11.2%. What is thr corporation's weighted average cost of capital? Submit your answer as a percentage and round to two decimal places (Ex. 0.00%)