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Raw data


Comparing the mean incomes of males and females using survey data from 1993.



Two-Sample Difference of Means


Independent Variable: SEX

Dependent Variable: INCOME


Sample One: 0 Female

Sample Two: 1 Male


                         Sample 1         Sample 2

                         Female           Male   


Sample Mean              12279.4667       15266.4706

Std Deviation             4144.6323        3947.7352

Sample Size (n)             15                17



                        Homogeneity of Variance


              F-ratio   1.09     DF (14, 16)   p < 0.4283 A



                  T-statistic          DF     p < (2-tailed)


Equal Variance        -2.0870       30             0.0455 B

Unequal Variance      -2.0800       31.05         0.0459






A  The F-ratio is not statistically significant. Therefore, use the equal variance test statistic.

B  For a 2-tailed test, the p-value represents the probability of making a type 1 error (concluding there is statistical significance when there is none).  Since there is about 4.6% (p < .0455) chance of making a type 1 error, which does not exceed the 5% error limit (p=.05) established in the rejection criteria of the hypothesis testing process (alpha), you conclude there is statistical significance.




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