Critical Value Calculator. Use this calculator for critical values to easily convert a significance level to its corresponding Z value, T score, F-score, or Chi-square value. Outputs the critical region as well. The tool supports one-tailed and two-tailed significance tests / probability values. t-testtable.htm. Table of critical values of. t. : One Tailed Significance level: df: Two Tailed Significance level: 0.2. 0.1. What critical value should be compared to the t value obtained as the test statistic? Solution: The sample size is 12. Hence the degrees of freedom ( df) = 12 - 1 = 11. Mapping the alpha level across the row for one-tailed alpha values and the df of 17 on the left-side of the table, we get our critical value as 1.363. When is T Distribution used? .

one tailed critical value table