XYZ stock price and dividend history are as follows:

An investment manager buys three shares of XYZ at the beginning of 2015, buys two more shares at the beginning of 2016, sells one share at the beginning of 2017, and sells all four remaining shares at the beginning of 2018. (a) What are the arithmetic and geometric average returns the manager earned with this strategy? (b) What is the dollar-weighted return?

Year Beginning-of-year-price Dividend Paid at Year End 2015 $ 100 $4 2016 $ 120 $4 2017 $ 90 $4 2018 $ 100 $4