Questions 6-10

6. According to a study conducted by a statistical organization, the proportion of people who are satisfied with the way things are going in their lives is 0.85. Suppose that a random sample of 100 people is obtained. Complete parts (a) through (b) below. ' . ' 3. Suppose the random sample of 100 people is asked, "Are you satisfied with the way things are gomg in your life?" Is the response to this question qualitative or quantitative? b. in the sample obtained in part (a), what is the probability that the proportion that is satisfied with the way things are going in their life exceeds 90? Round your answers to two decimal places. 7. Construct and interpret a 99% confidence interval of the population proportion at the given level of confidence. x = 75, n = 110. Round your answers to two decimal places. 8. A television sports commentator wants to estimate the preportion of citizens who "follow professional football." a) what sample size should be obtained if he wants to be within 2.5 percentage points with 90% confidence if he uses an estimate of19% obtained from a poll? Show formula and round up your final answer. b) What sample size should be obtained if he wants to be within 3 percentage points with 95% confidence if he does not use any prior estimates? Round up your answer. 9. A researcher wishes to estimate the average blood alcohol concentration (BAC) for drivers involved in fatal accidents who are found to have positive BAC values. He randomly selects records from 85 such drivers in 2009 and determines the sample mean BAC to be 0.12 g/dL with a standard deviation of 0.04 g/dL. Determine and interpret a 99% confidence interval for the mean BAC in fatal crashes in which the driver had a positive BAC. Show formula and final answer to two decimal places. . . i la 10. A Simple random sample of size n is drawn from a population that is known to be normally d'Str'bUIed' Thle ESP" variance, $2, is determined to be 13.1. Construct and interpret a 95% confidence interval for 02 and a if the samp e , is 24. Show formula and final anSWer to two decimal places