Suppose that a random sample of 11 adults has a mean score of 79 on a standardized personality test, with a standard deviation of 7 . (A higher score indicates a more personable participant.) If we assume that scores on this test are normally distributed, find a 90% confidence interval for the mean score of all takers of this test. Then find the lower limit and upper limit of the 90%

A prominent medical group claims that the population mean of the surgery durations for all brain tumor patients is 3.69 hours. You are a data analyst for a health insurance company and want to test that claim. To do so, you select a random sample of 32 brain tumor surgery patients, and you record the surgery duration for each. Assume it is known that the population standard deviation of the durations of all brain tumor surgeries is 1.68 hours. Based on your sample, follow the steps below to construct a 99% confidence interval for the population mean of the surgery durations for all brain tumor patients. Then state whether the confidence interval you construct contradicts the medical group's claim. (If necessary, consult a list of formulas.) (a) Click on "Take Sample" to see the results from your random sample of 32 brain tumor patients. (b) (c) Take Sample Sample size: Point estimate: Population standard deviation: Critical value: Compute 0.00 0.00 Number of patients Enter the values…

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.

If n=14, ¯xx¯(x-bar)=34, and s=4, construct a confidence interval at a 80% confidence level. Assume the data came from a normally distributed population.