XYZ stock price and dividend history are as follows: Beginning-of-Year Dividend Paid at Year Price Year-End 2015 $108 $4 2016 112 2017 98 2018 103 An investor buys four shares of XYZ at the beginning of 2015, buys another three shares at the beginning of 2016, sells one share at the beginning of 2017, and sells all six remaining shares at the beginning of 2018. a. What are the arithmetic and geometric average time-weighted rates of return for the investor? (Do not round intermediate calculations. Round your answers to 2 decimal places.) % Arithmetic mean Geometric mean %