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. a. Calculate the time-weighted geometric average return on this "portfolio." (Do not round intermediate calculations. Round your answer to 2 decimal places.) b. Calculate the time-weighted arithmetic average return on this portfolio. (Do not round intermediate calculations. Round your answer to 2 decimal places.) c. Calculate the dollar-weighted average return on this portfolio. (Do not round intermediate calculations. Round your answer to 2 decimal places.)