3. (6 marks) 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 Price $90 $100 $100 $105 Action Buy 4 shares Sell 1 share Sell 1 share Sell 2 share 2 3 (a) (4 marks) Calculate the time-weighted geometric average return and arithmetic average re- turn on this portfolio. (b) (2 marks) Calculate the dollar-weighted average return on this portfolio