please show your work.

Royal Petroleum Co. can buy a piece of equipment that is anticipated to provide a 12 percent return and can be financed at 9 percent with debt. Later in the year, the firm turns down an opportunity to buy a new machine that would yield a 19 percent return but would cost 21 percent to finance through common equity. Assume debt and common equity each represent 50 percent of the firm's capital structure at 6 percent cost of debt and 18 percent cost of equity. a. Compute the weighted average cost of capital. (Round the final answer to 1 decimal place.) Weighted average cost of capital b. Which project(s) should be accepted? New machine should be financed. Piece of equipment should be financed