For the following group data calculate a ttest and test for

For the following group data, calculate a t-test and test for significance at the .05 level, 2-tailed level of significance.

                        Treatment Group                    Control Group

                        Mean = 68.4                           Mean = 52.2

                        sd = 5.6                                   sd = 6.0

                        n = 42                                      n = 46

Solution

P value and statistical significance:   The two-tailed P value equals 0.0528   By conventional criteria, this difference is considered to be not quite statistically significant. Confidence interval:   The mean of Group One minus Group Two equals 16.20000   95% confidence interval of this difference: From -0.20133 to 32.60133 Intermediate values used in calculations:   t = 1.9635   df = 86   standard error of difference = 8.250