Which of the following is the best way to reduce the variances in the distributions of means when conducting a t test for independent means?
A)Increase the size of the samples
B)Raise the study's level of significance
C)Use the true population variance
D)Treat the two samples as one sample

Question

Quizplus · Accepted Answer

Increasing the size of the samples will decrease the variances in the distributions of means, resulting in a more precise estimate of the population means and a narrower confidence interval. This will in turn increase the power of the statistical test and make it more likely to detect a significant difference between the means of the two groups. Raising the study's level of significance will have the opposite effect by increasing the probability of a Type I error (i.e. rejecting the null hypothesis when it is actually true). Using the true population variance is often not feasible or practical, as it usually requires prior knowledge or assumptions about the population distribution, which may be unknown or untestable. Treating the two samples as one sample is equivalent to running a paired t-test, which assumes that there is a one-to-one correspondence between the observations in both groups, and thus may not be appropriate for independent or heterogeneous samples.

Which of the Following Is the Best Way to Reduce