A researcher wishes to estimate the proportion of adult males who are less than 5 feet 5 inches tall. She wants to be 90% confident that her estimate is within 4% of the true proportion (Round to the nearest whole number): (a) How large a sample should be taken if in a sample of 300 males, 30 were less than 5 feet 5 inches tall? (b) If no estimate of the sample proportion is available, how large should the sample be?

Suppose that the result of a public opinion poll shows that just 10% of people would be willing to give up their cell phones for 1 week in exchange for $100. How many people would need to be surveyed in order to have a margin of error of ±2%?

The brand manager for a brand of toothpaste must plan a campaign designed to increase brand recognition. He wants to first determine the percentage of adults who have heard of the brand. How many adults must he survey in order to be 95​% confident that his estimate is within five percentage points of the true population​ percentage? n=?

You want to obtain a sample to estimate a population proportion. Based on previous evidence, you believe the population proportion is approximately 12%. You would like to be 90% confident that your estimate is within 4.5% of the true population proportion. How large of a sample size is required?

For this problem, carry at least four digits after the decimal in your calculations. Answers may vary slightly due to rounding.A random sample of 5280 permanent dwellings on an entire reservation showed that 1620 were traditional hogans.

For this problem, carry at least four digits after the decimal in your calculations. Answers may vary slightly due to rounding.In a survey of 1000 large corporations, 246 said that, given a choice between a job candidate who smokes and an equally qualified nonsmoker, the nonsmoker would get the job. (a) Let p represent the proportion of all corporations preferring a nonsmoking candidate. Find a point estimate for p. (Round your answer to four decimal places.)(b) Find a 0.95 confidence interval for p. (Round your answers to three decimal places.) lower limit       upper limit       What is the margin of error based on a 95% confidence interval? (Round your answer to three decimal places.)

With no preliminary estimate of the proportion known, how many young adults would you survey to state with 99% confidence that the estimated proportion is within 10% of the true proportion?

What percentage of your campus student body is female? Let p be the proportion of women students on your campus.

You want to obtain a sample to estimate a population proportion. Based on previous evidence, you believe the population proportion is approximately 56%. You would like to be 98% confident that your estimate is within 3.5% of the true population proportion. How large of a sample size is required?

A sample of students is to be selected to estimate the proportion who have recieved a medical examination during the past year.  The survey found that x =567 students were examined during the past year.  Construct a 95% interval estimate of the population proportion if the sample size was n=700