## E.5 Answers to Lecture 5 tutorial

**Return to index of tutor information.**

### E.5.1 Answers to Sect. 5.1

Answers embedded.

- 70% directly from the table.
- \(281/(404 - 281) - 2.28\).
- For patients treated with ETI, about 278 die for every 100 that survive.
- \(2.78/2.28 = 1.22\).

### E.5.2 Answers to Sect. 5.2

- \(45\div 240=18.75\)% of all college students in the sample have received one concussion, the same for all student types.
- Not sure which is best; they do different things. I’d probably prefer (c).
- Odds (non-athlete receiving 2+ concussions) is \(21\div(81-21) = 21\div 60 = 0.35\). Non-athletes are 0.35 times as likely to receive two or more concussions than fewer than two. Or: For every 100 students with fewer than two concussions, there are 35 with two or more.
- Odds (soccer player receiving 2+ concussions) is \(13\div(63-13) = 13\div 50 = 0.26\). Soccer players are 0.26 times more likely to receive two or more concussions than fewer than two concussions.
- OR: \(0.35 \div 0.26\), or about \(1.35\). The odds of a non-athlete receiving two or more concussions is about 1.35 times the odds of a soccer player receiving two or more concussions (that is, smaller odds for soccer players).
- The better table is probably row percentages: The percentages of each type of students with given number of concussions.

### E.5.3 Answers to Sect. 5.3

Answers embedded.

- Relative frequency.
- Relative frequency.
- Subjective.
- Relative frequency.
- Classical.

### E.5.4 Answers to Sect. 5.4

Answers implied by H5P.

### E.5.5 Answers to Sect. 5.5

Answers embedded.

- Odds
**less than**one. - Odds
**less than**one. - Odds
**greater than**one. - Odds
**greater than**one.