A manager buys three shares of stock today, and then sells one of those shares each year for the next 3 years. His actions and the price history of the stock are summarized below. The stock pays no dividends. Time 0 1 2 3 Price $ 160 170 170 170 Action Buy 3 shares Sell 1 share Sell 1 share Sell 1 share a. Calculate the time-weighted geometric average return on this portfolio. (Do not round intermediate calculations. Round your answer to 2 decimal places.) Geometric average return % b. Calculate the time-weighted arithmetic average return on this portfolio. (Do not round intermediate calculations. Round your answer to 2 decimal places.) Arithmetic average return c. Calculate the dollar-weighted average return on this portfolio. (Do not round intermediate calculations. Round your answer to 2 decimal places.)