What is the main difference between Z score and t score?
A)t scores are used when the study requires a one-tailed test
B)t scores are used when the population variance is unknown
C)t scores are used whenever the sample size is greater than 30
D)t scores are only used when inferences are made about other samples

Question

Quizplus · Accepted Answer

The main difference between Z score and t score is that t score is used when the population variance is unknown, while Z score is used when the population variance is known. T score is a more appropriate measure when the sample size is small (less than 30) and the population standard deviation is unknown, while z scores are used when sample sizes are larger and the population is known.

What Is the Main Difference Between Z Score and T