Use a t-table, software, or a calculator to estimate the following critical values. a) The critical value of t for a 95% confidence interval with df = 27. b) The critical value of t for a 99% confidence interval with df = 81. Click the icon to view a t-distribution table of critical values. a) What is the critical value of t for a 95% confidence interval with df = 27? (Round to two decimal places as needed.)