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.