The mean gestational age of infants born to mothers who smoke is compared to mothers who did not smoke with the following resultin SPSS

The t value for this analysis is[a]with a p value of[b]. The total size of both groups (smokers and non-smokers) is[c]. Based on this result we[d]reject/fail to reject the null hypothesis (alpha = 0.05.

T-Test Group Statistics toxemia diagnosis for Std Std. Error mother N Mean Deviation Mean gestational age Yes 21 30.90 2.322 507 No 79 28.35 2.321 261 Independent Samples Test Levene's Test for Equality of Variances t-test for Equality of Means 95% Confidence Interval of Sig. (2- Mean Std. Error the Difference 71 Sig. df tailed) Difference Difference Lower Upper gestational age Equal variances assumed 017 .898 4.476 98 000 2.550 570 1.420 3.681 Equal variances not assumed 4.475 31.465 .000 2.550 .570 1.389 3.712