A survey of folk music fans yield this 95% confidence interval estimate of the proportion of fans who love the music of David Wilcox :  0.74 to 0.86.   To the nearer percentage point the margin of error for the survey is

A random sample of 300 college freshmen found that 112 of them own an iPhone. Find a 95% confidence interval for the true proportion of college freshmen that own an iPhone. Show all work leading up to your answer below.

A random sample of high school students is used to estimate the mean time all high school students study for Algebra II tests. A 99% confidence interval based on this sample is: 1.7 hours to 3.1 hours.  What is the sample mean?

50 of the 600 medical students who were chosen at random stated they intended to work in a rural area. Calculate the 90% confidence interval for the actual percentage of medical students who intend to practice in rural areas. The responses shown here are estimates.

If you want to be confident in your estimation of a confidence interval, you should use….

A survey of 32,782 adults in 2004 indicated that 24.6% of adults were current smokers. A similar study conducted in 1995 of 40,000 adults indicated that 29.7% were current smokers. a. Find and interpret a point estimate of the difference between the proportion of current smokers in 1995, and the proportion of current smokers in 2004. b. A 95% confidence interval for the true difference is (-0.058,-0.045). Interpret. c. What assumptions must you make for the confidence interval i part b to be valid? (…) a. Find a point estimate of the difference between the proportion of current smokers in 1995 and the proportion of current smokers in 2004. (Round to three decimal places as needed.)

Researchers studied the mean egg length (in millimeters) for a bird population. After taking a random sample of eggs, they obtained a 95% confidence interval of (45,60). What is the value of the margin of error? Choose the correct answer below. A. 15 mm B. 52.5 mm O c. 7.5 mm O D. 1.96

i need the answer quickly