You are testing the difference between two population means.Which of the following best describes the pooled sample standard deviation under the assumption that the two population standard deviations are equal for small samples?
A)it is the square root of the weighted average of the sample variances, weighted by their respective degrees of freedom
B)it is a simple average of the sample standard deviations
C)it cannot be calculated for small samples
D)it is the square of the differences of the sample variances
E)none of the above

Question

Quizplus · Accepted Answer

The pooled sample standard deviation, under the assumption that the two population standard deviations are equal for small samples, is indeed the square root of the weighted average of the sample variances, where the weighting is done by their respective degrees of freedom. This approach allows for a more accurate estimate of the common standard deviation of the two populations.

You Are Testing the Difference Between Two Population Means