Math 2208 quiz 8 | Complete Solution

Math 2208 - Chapters 16-18 - CI and Testing of hypothesis for p
Take home quiz 8

Due: November 24th (in class)
Q.1: Suppose that 65 of 100 randomly sampled people in NS answered \yes" to question of whether
they would vote in the next municipal election.
1. Construct a 99% con dence interval for the proportion of all NS's who would answer yes.
2. Interpret the interval.
3. Instead of a 99% CI, you wanted to construct a 95% CI. Which interval has a larger margin of
error? Why?
4. How large a sample would you need to take to estimate the proportion, if you wanted to
maintain 99% con dence, with a margin of error of 5%?
5. Con rm that the assumptions and conditions are satis ed. Explain in context.
Q.2: Researches in US feel that fewer than 18% of US adults read one or more adventure books in
the last year. A simple random sample of 280 US adults showed that 35 read one or more adventure
books. We want to know if the data support the researches feeling.
(1) 1. What is the parameter of interest?
(2) 2. State hypotheses.
(2) 3. Verify assumptions, conditions satis ed.
(3) 4. Find test statistic.
(2) 5. Find P-value.
(1) 6. Give brief conclusion.
(1) 7. State conclusion in context of problem.
(2) 8. Interpret P-value as a probability in context.
(1) 9. Is there any kind of error you could make when you test this hypothesis? Explain.
(1) 10. What is the conclusion if you want to test the researchers feeling at 0.05 signi cance level?