4.1. Introduction4.2. Case Study: Is Our Expensive New Search Engine At Behemoth.Com Better Than What We Already Have?4.3. Hypothesis Testing Using the Chi-Square Test of Independence or Fisher’s Exact Test4.4. Meanwhile, Back At Behemoth.Com4.5. Binomial Confidence Intervals and the Adjusted Wald Method4.6. Summary4.7. Addendum 1: How to Run the Chi-Square Test for Different Sample Sizes4.8. Addendum 2: Comparing More than Two Treatments4.9. Appendix: Confidence Intervals for all Possible Sample-Proportion Outcomes From N = 1 to N = 15, in Table A.14.10. Exercises