Find the minimum sample size n needed to estimate u for the given values of c, o, and E. C=0.98, o =9.6, and E =2 Assume that a preliminary sample has at least 30 members n= (Round up to the nearest whole number.) Construct the confidence interval for the population mean j. C=0.90, x =9.8, 6=04, and n =56 A 90% confidence interval for u is () (Round to two decimal places as needed.)