C.10. From Chapter 13

Comparing Two Proportional Data Samples (95% Confidence)

We must calculate a test value Zt.

x1 = number of defects (or whatever) in sample #1

x2 = number of defects (or same as above) in sample #2

absolute proportion difference (no minus sign in difference)

n1 = size of sample #1

n2 = size of sample #2

If Zt > 1.96, then we can say with a 95% confidence that the two samples are significantly different.

C.10.1. Use on Problem Type

Use this formula on proportional data when you want to test if two samples are significantly ...

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