In a recent survey of a fair stratified random sample of the population, a question appeared as: Do you plan to vote in favour of the speed limit change? Yes/No scientist found the following number of responses per stratum:

	Age 20-24	Age 25-29	Age 30-34
Yes	45	80	5
No	25	25	15
No response	25	10	55

1. What are two reasons a respondent might not answer this question?
2. What are the strata in this sample?
3. If a person is picked at random from the sample, what is the probability that they are age 25-29 or did not respond to this question?
4. If three people are picked at random from the sample, what is the probability that at least one did not respond to this question?
5. If we assume there is no bias, what conclusions can be drawn about the population's opinion of the speed limit change? Justify your response.
6. How would your answer to (e) change if we found out that 90% of those who did not respond are actually against the change?