A firm has a common stock with a market price $55 per share and an expected dividend of $2.81 per share at the end of the coming year. The dividends paid on the outstanding stock over the past five years are as follows:
Year 1 - $2.00
Year 2 - $2.14
Year 3 - $2.29
Year 4 - $2.45
Year 5 - $2.62
What is the cost of the firm's common stock equity?