Confidence Interval: Basics 1. A Gallup Poll in November 2014 found…
Question Answered step-by-step Confidence Interval: Basics 1. A Gallup Poll in November 2014 found… Confidence Interval: Basics1. A Gallup Poll in November 2014 found that 59% of the people in its sample said “Yes” when asked, “Would you like to lose weight?” Gallup announced: “For results based on the total sample of national adults, one can say with 95% confidence that the margin of (sampling) error is ±3 percentage points.”(a) Explain what the margin of error means in this setting. (b) State and interpret the 95% confidence interval.(c) Interpret the confidence level.2. The admissions director from Florida International University found that (107.8, 116.2) is a 95% confidence interval for the mean IQ score of all freshmen. Comment on whether or not each of the following explanations is correct.(a) There is a 95% probability that the interval from 107.8 to 116.2 contains μ. (b) There is a 95% chance that the interval (107.8, 116.2) contains X.(c) This interval was constructed using a method that produces intervals that capture the true mean in 95% of all possible samples.(d) 95% of all possible samples will contain the interval (107.8, 116.2).(e) The probability that the interval (107.8, 116.2) captures μ is either 0 or 1, but we don’t know which.3. How do Confidence Intervals Change…(a) How does the shape of the confidence interval change if the confidence level increases from 90% to95%?(b) How would the shape of a confidence change if the sample size was decreased? Assume the new, smaller sample size still meets all of the normality conditions. Math Statistics and Probability STAT E100 Share QuestionEmailCopy link Comments (0)
