## D.14 Answers: Numerical summaries for qualitative data

Answers to exercises in Sect. 14.9.

Didn’t vomit: 0.738 had beer then wine, 0.262 had wine only. They tell us the proportion that drank various things, among those who did and didn’t vomit. 2. Beer then wine: 8.8% vomited and 91.2% didn’t; Wine only: 21.4% vomited and 78.6% didn’t. They tell us the percentage that vomited, for each drinking type. 3. $$(6 + 6)/(6 + 6 + 62 + 22) = 0.125$$. 4. $$6/22 = 0.2727$$. 5. $$6/62 = 0.096774$$. 6. $$0.27272/0.096774 = 2.82$$. 7. $$0.096774/0.27272 = 0.354$$.
Answer to Exercise 14.2: 1. $$91/(91 + 188) = 0.32616$$. 2. $$188/91 = 2.0659$$, or about 2.07. 3. $$22/13 = 1.6923$$, or about 1.69. 4. $$13/(13 + 22) = 0.37142$$, or about 37.1%. 5. $$2.0659/1.6923 = 1.22$$.