When Calculating a Confidence Interval for a Independent Samples T-Test

Multiple Choice

When calculating a confidence interval for a independent samples t-test instead of a one-sample t-test, which of the following best describes the difference in their calculations?

A) Instead of the population standard deviation, you use the sample standard deviation.
B) Instead of the population mean, you use the sample mean.
C) You use difference scores instead of the sample mean.
D) The critical values are different