Chi-square
Test for non-inferiority
Start by entering the reference proportion and your test proportion.
[Enter decimals, not percentages: 0.25 for 25%]
Reference proportion:
Test proportion:

To demonstrate non-inferiority, you can change any one of the values below.
Then click 'Result'.
Threshold for proportion difference:
Proportion that test proportion is to be different from:
Difference that effect exceeds:

Click here for sample size:
You will need subjects in Group 1
You will need subjects in Group 2
For different power or significance level, change the fields below:
Alpha: Prob(reject H0 when H0 is true)
Power: Prob(reject H0 when H1 is true)
For unequal sample sizes, change the ratio below:
Group2/Group1:
Choose another study design
v. 03/03
Contact: sfh2@columbia.edu
Source: J.L. Fleiss, et al.
Statistical Methods for Rates and Proportions (3rd ed., p. 76, Table A.4)