zonk corp. is a manufacturer of ball bearings. data below is in dollar amounts in millions: total assets $7460 interest-bearing debt $3652 average pre-tax borrowing cost 10.5% common equity: book value $2950 market value $13685 income tax rate 35% market equity beta 1.13 assuming that riskless rate is 4.6% and the market premium is 7.3%, calculate zork's cost of equity capital.