Give a 95​% confidence interval for the true proportion of those from their entire mailing list who may donate.   ​(b) A staff member thinks that the true rate is 4.8​%. Given the confidence interval you​ found, do you find that rate​ plausible?

A 90% confidence interval for the difference between the proportion of college students who use flash cards for studying and high school students who use flash cards for studying is (0.13, 0.23). Then the Error is +5%. True False

A survey of randomly selected university students found that 91 of the 101 first-year students and 96 of the 136 second-year students surveyed had purchased used textbooks in the past year. (a) Construct a 95% confidence interval for the difference the proportions of first-year and second-year university students who purchased used textbooks. (Round your answers to 4 decimal places, if needed.) Answer: (b) If a 98% confidence interval for the difference in proportion of first-year and second-year university students who purchased used textbooks is (0.0809, 0.3093). Give an interpretation of this confidence interval. O We are 98% confident that the first-year students at this university bought between 8.09% and 30.93% more used textbooks than second-year students. O We know that 98% of the first-year students bought between 8.09% and 30.93% higher than the proportion of second-year students who bought used textbooks. O We are 98% confident that, at this university, the proportion of…

A random sample from a population of adults consists of 67 men and 43 women. (a) Give a 95% confidence interval for the proportion of men in the population. (b) Interpret that confidence interval.