Question

2. Critical Values from the t-table (Table D) (a) Accurate to the nearest 3 decimal places, what is the critical value (t or z*) that corresponds to the given confidence levels and degrees of freedom? Fill in the following table with the appropriate critical values from the t-table (table D). Remember to truncate down the df when the exact value is not listed in the table. a unknown (t) df- 12 df- 29 df 71 Confidence level σ known (r) 60% 90% 96% 99.5%

Answer 1

confidence level                                 $\sigma$ unknown(t^*)                                                        $\sigma$ known(z^*)

                                               df = 12                  df = 29                    df = 71

60%   0.873                  0.854    0.847                        0.842                                    

90%                                       1.782                   1.699                        1.667                         1.645

96%                                       2.303                    2.150                        2.092                         2.054                                          

99.5%                                     3.428                    3.038                       2.897                         2.807