Calculate Sir Speedy's weighted cost of each source of capital and the weighted average cost of capital

Sir Speedy's capital structure is as follows:

Debt: 17%

Preferred Stock: 0%

Common Equity: 83%

The pretax cost of debt is 3.75 percent. The aftertax is 3.15 perfect, the cost of preferred stock is 5.50 percent; and the cost of common equity (in the form of retained earnings) is 7.00 percent.

Calculate Sir Speedy's weighted cost of each source of capital and the weighted average cost of capital