(Holding-period dollar gain and return) Suppose you purchased 15 shares of Diamond Company stock for $28.13 per share on May 1, 2016. On September 1 of the same year, you sold 15 shares of the stock for $25.20. Calculate the holding-period dollar gain for the shares you sold, assuming no dividend was distributed, and the holding-period rate of return. a. The holding-period dollar gain for the shares you sold is $ Enter a negative number if it is a loss. (Round to the nearest cent.)