Bayes Probabilities 52E9A2
1. **State Bayes’ theorem:**
Bayes’ theorem relates conditional probabilities and is stated as:
$$P(A|B) = \frac{P(B|A)P(A)}{P(B)}$$
where $P(A|B)$ is the probability of event A given B has occurred.
2. **Problem:** Given the survey data:
| Gender | Yes | No | Total |
|--------|-----|----|-------|
| Male | 32 | 18 | 50 |
| Female | 8 | 42 | 50 |
| Total | 40 | 60 | 100 |
Find:
(1) Probability respondent answered yes given female.
(2) Probability respondent was male given answered no.
3. **Formulas:**
- Conditional probability: $P(A|B) = \frac{P(A \cap B)}{P(B)}$
4. **Calculations:**
(1) $P(\text{Yes} | \text{Female}) = \frac{\text{Number of females who said yes}}{\text{Total females}} = \frac{8}{50} = 0.16$
(2) $P(\text{Male} | \text{No}) = \frac{\text{Number of males who said no}}{\text{Total no}} = \frac{18}{60} = 0.3$
**Final answers:**
(1) $0.16$
(2) $0.3$