Can someone please explain how to do these on a financial calculator? I have my final tomorrow.

DQuestion 14 1 pts firm recently paid a dividend of $4 to common stockholders. Dividends are expected to grow at 8% per year for the foreseeable future. The current stock price is $54 A $15 million bank line of credit is available with an interest rate of 9%. The firm's tax rate is 34%. What is the firm's cost of capital if their capital structure consists of 60% equity and 40% bank loans? 0 11.98% O 12.58% 0 13.21% 0 14.60% O 15.20% DQuestion 15 1 pts Last year, Cayman Corporation had sales of $7,000,000, total variable costs of $3,000,000, and total fixed costs of $1,500,000. In addition, they paid $480,000 in interest to bondholders. Cayman has a 35% marginal tax rate. If Cayman's sales increase 7%, what should be the increase in operating income? O 13.3% O 13.9% O 10.8% O 11.2% 8.7%