Which condition must be met to conduct a test for the difference in two sample means using a z-statistic?
A)The data must be at least of nominal scale.
B)The populations must be normal.
C)The two population standard deviations must be known.
D)The samples are dependent.

Question

Quizplus · Accepted Answer

The key condition for using a z-statistic in testing the difference between two sample means is that the two population standard deviations are known. This allows for the calculation of the standard error of the difference between the two means under the assumption of normal distribution.

Which Condition Must Be Met to Conduct a Test for the Difference