please post how you come about answer

annual returns -19.95 16.7% 19% -50% 43.2% 1.3% -16,6% What is the average annual return over the ten-year period (as a percent)? What is the standard deviation of annual returns over the ten-year period (as a percent) (Round your answer to two decimal places.) What is the 95% confidence interval on the return of this stock next year (as a percent) if the past average returns and volatility of returns are unbiased estimators of expected returns and future volatility (Round your answers to two decimal places.) tos Focus DE