$7-$ Your investment has a $10\%$ chance of losing $15\%,$ a $20\%$ chance of earning a $4\%$ rate of return, a $30\%$ chance of earning a $10\%$ rate of return, a $25\%$ chance of earning a $15\%$ rate of return, and a $15\%$ chance of earning a $20\%$ rate of return. What is your expected return on this investment?