need help for both 25 and 26. 25(top one) is calculating the average returns for stock A and 26 is the standard deviation

Given the following data for Stock A: (annual returns) Year 2012 2017 2012 Returns 40% 15% -10% Calculate the average returns for Stock A 3 6 10% 13.3% 15% 12 20% 15 18 Question 26 (1 point) Saved Given the following data for Stock A: (annual returns) Year 2017 2014 2012 Returns 40% 15% -10% Calculate the standard deviation of returns returns for Stock A: (approximately) 20%