You want to construct a 95% confidence interval for the performance of a large population of mutual funds. Assume returns are independent across funds, and the standard deviation of fund returns is 8.1 %. If you want the width of your interval to be 2.4 %, what sample size must you collect? Assume sample is large enough that the sample mean is normally distributed. Enter answer as the smallest integer sample that will accomplish your objective. I need it to be done on excel and please show the steps.