49. [-/3 Points] DETAILS MY NOTES You read in a report that a 90% confidence interval for the median income of American households was $51,027 : $338. Based on this interval, can you reject the null hypothesis that the mean income in this group is $50,000? O Yes O No What would be the alternative hypothesis? OH,: M # 50,000 OH,: H # 51,027 O Hy: H = 50,000 OH,: H = 51,027 What is the significance level? a = 50. [-/2 Points] DETAILS MY NOTES What type of shopping websites do males aged 18 to 34 visit? About 50% of male Internet users in this age group visit an auction site (such as ebay) at least once a month. (a) If we interview a random sample of 12 male Internet users aged 18 to 34, what is the probability that exactly 9 of the 12 have visited an auction site in the past month? (Round your answer to four decimal places.) (b) Suppose that we had interviewed a random sample of 500 men aged 18 to 34. What is the probability that at least 232 of the men in the sample visit an online auction site at least once a month? (Round your answer to four decimal places.)48. [-/2 Points] DETAILS MY NOTES The level of pesticides found in the blubber of whales is a measure of pollution of the oceans by runoff from land and can also be used to identify different populations of whales. A sample of six male minke whales in the West Greenland area of the North Atlantic found the mean concentration of the insecticide dieldrin to be x = 356 nanograms per gram of blubber (ng/g). Suppose that the concentration in all such whales varies Normally with population standard deviation a = 58 ng/g. Give a 95% confidence interval for estimating the mean level. (Round your answers to two decimal places.) to Ing/g 49. [-/3 Points] DETAILS MY NOTES You read in a report that a 90% confidence interval for the median income of American households was $51,027 : $338. Based on this interval, can you reject the null hypothesis that the mean income in this group is $50,000? Yes O No What would be the alternative hypothesis? OH, i H = 50,000 OH, : H # 51,027 O H, : A = 50,000 OH, : M = 51,027 What is the significance level? a = Submit Answer 50. [-/2 Points] DETAILS MY NOTES What type of shopping websites do males aged 18 to 34 visit? About 50% of male Internet users in this age group visit an auction site (such as eBay) at least once a month. (@) If we interview a random sample of 12 male Internet users aged 18 to 34, what is the probability that exactly 9 of the 12 have visited an auction site in the past month? (Round your answer to four decimal places.) (b) Suppose that we had interviewed a random sample of 500 men aged 18 to 34. What is the probability that at least 232 of the men in the sample visit an online auction site at least once a month? (Round your answer to four decimal places.)41. [-/2 Points] DETAILS MY NOTES At what age do infants speak their first word of English? Here are data on 20 children (in months). 15 26 10 15 20 18 11 8 20 7 9 10 11 10 12 17 11 10 Is there good evidence that the mean age at first word among all normal children is greater than age one (year)? Determine the test statistic and P-value. Ot = 0.203, 0.15 0.25 O t = 0.907, 0.15 0.2 O t = 0.907, P
