Concerning inference on two independent population means, the pooled variance estimate is:
A) a way of estimating variance that relies on the information provided by only one of the samples.
B) an unbiased estimator of the parameter .
C) a combined (using a weighted average) estimate for the unknown variance of two populations.
D) a less efficient but easier way of estimating population variances as compared to using two separate variance estimates (one for each population).

Question

Concerning inference on two independent population means, the pooled variance estimate is:
A) a way of estimating variance that relies on the information provided by only one of the samples. 
B) an unbiased estimator of the parameter . 
C) a combined (using a weighted average) estimate for the unknown variance of two populations. 
D) a less efficient but easier way of estimating population variances as compared to using two separate variance estimates (one for each population).

Quizplus · Accepted Answer

The pooled variance estimate is a combined estimate for the unknown variance of two populations. It is calculated using a weighted average of the sample variances from two independent samples. This estimate is unbiased and provides a more efficient estimate of the population variances compared to using two separate variance estimates (one for each population).

Concerning Inference on Two Independent Population Means, the Pooled Variance