Rank the following three stocks by their risk-return relationship, best to worst. Rail Haul has an average return of 15 percent and standard deviation of 31 percent. The average return and standard deviation of Idol Staff are 18 percent and 26 percent; and of Poker-R-Us are 12 percent and 20 percent.
rank / stock
1 / .....
2 / ......
3 /......