A random sample of 400 items reveals that 312 of the items have the attribute of interest. a. What is the point estimate for the population proportion for all items having this attribute? b. Use the information from the random sample to develop a 99% confidence interval estimate for the population proportion, p, of all items having this attribute of interest. a. The point estimate is (Round to two decimal places as needed.)

A doctor wants to estimate the mean HDL cholesterol of all​ 20- to​ 29-year-old females. How many subjects are needed to estimate the mean HDL cholesterol within 3 points with 99% confidence assuming s=17.8 based on earlier​ studies? Suppose the doctor would be content with 99% confidence. How does the decrease in confidence affect the sample size​ required? a. A​ 99% confidence level requires _______ subject. b. 90% confidence level requires ________ subject. c.How does the decrease in confidence affect the sample size​ required? a.Decreasing the confidence level decreases the sample size needed.   b.Decreasing the confidence level increases the sample size needed.   c.The sample size is the same for all levels of confidence.

Tina catches a 14-pound bass.  She does not know the population mean or standard deviation.  So she takes a sample of five friends and they say the last bass they caught was 9, 12, 13, 10, and 10 pounds.  Find the t and calculate a 95% (α = .05) confidence interval.

Out of 500 people sampled, 365 had kids. Based on this, construct a 95% confidence interval for the true population proportion of people with kids.Give your answers as decimals, to three places______ < p < _____