We wish to estimate what percent of adult residents in a certain county are parents. Out of 600 adult residents sampled, 264 had kids. Based on this, construct a 99% confidence interval for the proportion ππ of adult residents who are parents in this county. Give your answers as decimals, to three places.

Nearly one-half of Americans ages 25 to 29 are unmarried. How large a sample is necessary to estimate the true proportion of unmarried Americans in this age group within 2 percentage points with 95% confidence?

We wish to estimate what percent of adult residents in a certain county are parents. Out of 200 adult residents sampled, 134 had kids. Based on this, construct a 99% confidence interval for the proportion, p, of adult residents who are parents in this county.Give your answers as decimals, to three places.

A Gallup survey of 2324 adults (at least 18 years old) in the U.S. found that 417 of them have donated blood in the past two years. Construct a 90% confidence interval for the population proportion of adults in the U.S. who have donated blood in the past two years. Round your answer to three decimal places. Use Z = 1.645. Use the unrounded values in Excel to find the answers to #2, #3 and #4 1. Find the sample proportion of adults in the U.S. who have donated blood in the past two years. Round your answer to three decimal places. 2. The standard error for sample proportion has a value of V 3. The margin of error has a value of 4. Construct the 90% confidence interval for adults who have donated blood in the past t