Suppose you do not know the population mean fee charged to H&R Block customers last year. Instead, suppose you take a sample of size n-8 and find a sample mean of 350. Assume that the distribution for fees is normally distributed with a sample standard deviation of $100. Note that you are given sample standard deviation in this question compared to population standard deviation question 2 (previous question). Before conducting the survey, suppose you believed based on your previous observations, your best guess for population standard deviation of fee charged to H&R Block is $50. With this assumption in mind, What should your sample size n approximately be if you want: Margin-of-Error of to be 2 % and confidence level to be 95 %? Margin-of-Error of to be 4% and confidence level to be 95%? Margin-of-Error of to be 4 % and confidence level to be 99%? ii. 90% confidence interval for the population mean of fees H&R Block. i. Calculate the margin of error (MOE) of x using a 10% significance level. Calculate the 90 % confidence interval. Suppose an analyst belief that the population mean fee is equal to $185. Using a 90% confidence level. can we conclude the analyst is right? Why or why not? a. b. с.