3. How large a sample must be selected if the company wants to be 98% confident that their estimate is going to be within $500 of the true mean weekly salary? (Recall the sample size must be rounded up to the next whole number at the end) Zo58. (a) To find the minimum sample size we use the formula: n = (%)2, where Z_ is the critical value, S, is sample standard deviation (this is the best estimator since we do not have the population standard deviation) and E is the margin of error. (b) To find the critical value for a 98% confidence interval we follow the same procedure as specified in question 2(a). AI'IS: Zgac% - (c) The sample standard deviation was obtained in question (1), the margin of error is given to be $500. Use the formula to find n. (Show all work, calculate the value and then round it up to the next whole number) Ans:n=