If one sample has n = 4 and SS = 90 and a second sample has n = 8 and SS = 150,then the estimated standard error for the sample mean difference is 9 points.

Question

Quizplus · Accepted Answer

The estimated standard error for the sample mean difference ($SE_{\bar{x}_1 - \bar{x}_2}$) is calculated using the formula $\sqrt{\frac{SS_1}{n_1(n_1-1)} + \frac{SS_2}{n_2(n_2-1)}}$. Plugging in the given values, we get $\sqrt{\frac{90}{4(4-1)} + \frac{150}{8(8-1)}} = \sqrt{\frac{90}{12} + \frac{150}{56}} = \sqrt{7.5 + 2.678} = \sqrt{10.178}$, which does not equal 9.

If One Sample Has N = 4 and SS =