In constructing a confidence interval for the population mean using the t-distribution we often need the degrees of freedom (d/), confidence level, and the critical value. Use the Student t-distribution to determine the missing values in the table below. Report the positive t critical value accurate to 3 decimal places. Sample Degrees of Confidence Critical size freedom level value (t) 24 % 2.500 27 90% 19 95% 19 % 2.861