Rumolt Motors has 17 million shares outstabding with a price of $27 per share. In addition, Rumolt has issued bonds with a total current market value of $521 million. Suppose Rumolt's equity cost of capital is 11%, and its debt cost of capital is 8%. a. What is Rumolt's pretax weighted average cost of capital? b. If Rumolt's corporate tax rate is 21%, what is its after-tax weighted average cost of capital