Now Playing: Tests for Two Proportions (3:59)

"PASS 13 is fantastic! Better than my new dishwasher and microwave combined."

Dr. Barbara Tabachnick, CSUN, Author

"PASS is a great program. It does so much and is easy to use. It’s much better than the other sample size programs I’ve used—it has helped me greatly in my research."

Ken Lawson, Ph.D., The University of Texas