Paired t-Test

Given two paired sets  and  of  measured values, the paired -test determines whether they differ from each other in a significant way under the assumptions that the paired differences are independent and identically normally distributed.

To apply the test, let

			(1)
			(2)

then define  by

(3)

This statistic has  degrees of freedom.

A table of Student's t-distribution confidence intervals can be used to determine the significance level at which two distributions differ.

REFERENCES:

Goulden, C. H. Methods of Statistical Analysis, 2nd ed. New York: Wiley, pp. 50-55, 1956.