Explain step by step but don't use excel

26) The following table shows the annual returns (in percent) Chevron and Caterpillar for Year 1 4. Year Chevron Caterpillar 35% 14% -20% 30% A UN - 3% 30% 15% 55% a. Which fund had the higher arithmetic average return? b. Which fund was riskier over this time period