MATH 225N Week 6 Assignment; Estimating Sample Size for a PopulationProportion

1. Question: Suppose an automotive repair company wants to determine the current percentage of customers who keep up with regular vehicle maintenance. How many customers should the company survey in order to be 95% confident that the estimated (sample) proportion is within 2 percentage points of the true population proportion of customers who keep up with regular vehicle maintenance? 2. Question: Suppose an automotive repair company wants to determine the current percentage of customers who keep up with regular vehicle maintenance. How many customers should the company survey in order to be 95% confident that the estimated (sample) proportion is within 4 percentage points of the true population proportion of customers who keep up with regular vehicle maintenance? 3. Question: Billy wants to estimate the percentage of students who live more than three miles from the school. He wants to create a 95%confidence interval which has an error bound of at most 3%. How many students should be polled to create the confidence interval? 4. Question: Billy wants to estimate the percentage of students who live more than three miles from the school. He wants to create a 95%confidence interval which has an error bound of at most 3%. How many students should be polled to create the confidence interval? 5. Question: Suppose a clothing store wants to determine the current percentage of customers who are over the age of forty. How many customers should the company survey in order to be90%confident that the estimated(sample)proportioniswithin4percentagepoints of the true population proportion of customers who are over the age of forty? 6. Question: Suppose an automotive repair company wants to determine the current percentage of customers who keep up with regular vehicle maintenance. How many customers should the company survey in order to be 90% confident that the estimated (sample) proportion is within 2 percentage points of the true population proportion of customers who keep up with regular vehicle maintenance?