Tim Trepid is highly risk-averse while Mike Macho actually enjoys taking a risk. Investments Returns: Expected Value Standard Deviation Buy stocks $ 9,300 $ 5,660 Buy bonds 7,580 2,390 Buy commodity futures 26,100 26,700 Buy options 14,200 13,600 a-1. Compute the coefficients of variation. (Round your answers to 3 decimal places.) a-2. Which one of the following four investments should Tim choose? Buy bonds Buy stocks Buy commodity futures Buy options b. Which one of the four investments should Mike choose?