XYZ 's stock price and dividend history are as follows: An Investor buys three shares of XYZ at the beginning of 2018, buys another two shares at the beginning of 2019 , sells one share at the beginning of 2020 , and sells all four remaining shares at the beginning of 2021. a. What are the arithmetic and geometric average time-weighted rates of return for the Investor? (Round your yearby-year rates of return and final answers to 2 decimal places. Do not round other calculations.) b. What is the dollar-weighted rate of return? (Hint. Carefully prepare a chart of cash flows for the four dates corresponding to the turns of the year for January 1,2018 , to January 1,2021 . If your calculator cannot calculate internal rate of return, you will have to use trial and error.) (Round your answer to 4 decimal places. Negative amount should be indlcated by a minus sign.)