I have come up with an answer for this, but I'm not sure I did it right.

Suppose Hornsby Ltd. just issued a dividend of $2.62 per share on its common stock. The company paid dividends of $2.12, S2.19, $2.36, and $2.46 per share in the last four years. If the stock currently sells for $81, what is your best estimate of the company's cost of equity capital using arithmetic and geometric growth rates? (Do not round intermediate calculations and enter your answers as a percent rounded to 2 decimal places, e.g., 32.16.)