Part I: Independent Samples t-test
The hypothesis being tested is: Women who are working will have a lower level of depression as compared to women who are not working.
- In the Polit2SetC dataset, 773 women were employed and 299 were not employed.
- The total sample size is 1072.
- The mean (SD) CES-D scores for the employed group is 16.18 (11.53) and for the non-employed group is 19.80 (11.63).
- The Levene’s statistic is 11.161, and the p-value is .001, indicating that the assumption of homogeneity of variance is violated. Equal variances are not assumed.
- The t-statistic is -4.222 with 1070 degrees of freedom and the p-value is < .001.
- The data supports the hypothesis that women who are working have a lower level of depression than women who are not working.
Part II: Paired Samples t-test
The hypothesis being tested is: Women who reported depression scores in wave 1 and wave 2 of the study did not have a significant difference in their level of depression.
- The total sample size is 1144.
- The mean (SD) CES-D scores at wave 1 is 16.12 (11.55) and at wave 2 is 14.51 (11.21).
- The mean difference between the two time periods is 1.61.
- The t-statistic is 3.999 with 1143 degrees of freedom and the p-value is < .001.
- The data does not support the hypothesis that there is no significant difference in depression scores between wave 1 and wave 2.
Part III: Independent Samples t-test for three outcomes
The outcomes variables are CES-D Score (cesd), SF12: Physical Health Component Score, standardized (sf12phys) and SF12: Mental Health Component Score, standardized (sf12ment).
The hypothesis being tested is: Women with no high school credential will have worse CES-D, physical health, and mental health scores than women with a diploma or GED.