Construct a 95% confidence interval to estimate the population mean when x - 121 and s = 31 for the sample sizes below. a) n= 20 b) n = 50 c) n= 80 Click here to view page 1 of the critical I-score table. Click here to view page 2 of the critical t-score table a) The 95%% confidence interval for the population mean when n = 20 is from a lower limit of 106.49 to an upper limit of 135.51 (Round to two decimal places as needed ) b) The 95% confidence Interval for the population mean when n = 50 is from a lower limit of to an upper limit of (Round to two decimal places as needed.)