I need help with these short statistics questions 1 Describe
I need help with these short statistics questions.
1. Describe the sampling distribution of p.
2. What is a confidence interval for p used for?
3. Interpret the meaning of a 90% confidence interval for the population proportion.
4. What is the effect of increasing the sample size in a confidence interval if all other quantities stay same?
5. What is the effect of increasing the confidence level in a confidence interval if all other quantities stay the same?
6. What are the requirements for a confidence interval of a single population proportion, large sample?
7. What is the formula for determining the sample size when estimating the population proportion?
Solution
1.The sampling distribution of p^ is normal with mean 0, standard deviation 1.
2.The confidence interval for p is:
P+/-z*p(1-p)/na
3.The 90% confidence interval for the population proportion contains the true population proportion with 90% confidence.
4.If the sample size is increased then the confidence interval gets narrower.
5.If the confidence level is increased then the confidence interval gets wider.
