Problem $9-7$ Risk versus Return $($LG$4)$ Rank the following three

stocks by their risk$-$return relationship, best to worst. Rail Haul

has an average return of $12$ percent and standard deviation of $24$

percent. The average return and standard deviation of Idol Staff

are $15$ percent and $35$ percent; and of Poker$-$R$-$Us are $9$ percent and $28$ percent$\mathrm{.}1.?2.?3.?$