Questions 7-10

QUESTION 7 Below are some examples of hypothesis testing questions. Match the correct test to the question. Heritage Union has said that 66% of us. adults have purchased life insurance. Suppose that for a random sample of 50 adults from a given us. city, a research finds that only 56% of A them have purchased life insurance. At a 0.05 level of significance test, is this sample finding ' V significantly lower than the 66% reported by Heritage Union? A. sample proportions, z-test, two-sided (tail) A scrap metal dealer claims that the mean of his cash sales is "no more than $80". But an - . . . . . B. sam le ro ortlons, z-test, one-Sided tail - 6 IRS agent believes the dealer Is untruthful. Observtng a sample of 20 cash customers, the p p p ( ) agent finds the mean purchased to be $91, with a standard deviation of $21. 0. sample means, t-test, two-sided (tail) A quality assurance inspector periodically examines the output of a machine to determine D. sample means, t-test, one sided (tail) whether it is properly adjusted. When set properly, the machine produces nails with a mean length of 2.0 inches and population standard deviation of 0.07 inches. For a sample of 35 E. sample means, Z-test, onesided (tail) nails, the mean length is 2.025 inches and sample standard deviation of 0.065 inches. . y F. sample means, z-test, IWO-Slded (tail) The director of admissions at a large unviersity says that 15% of high school juniors to whom , . - 6 she sends university pamphlets eventually apply for admission. In a sample of 300 students 6- sample means, t-test, "'S'dd (155") to whom materials were sent, 30 students applied for admission. It is believed that the average number of years of experience the employees at this location is 8.7 years. Examining a random sample of 15 employees, he finds the mean length to be 7.5 years with a standard deviation of 2.5 years. Does this sample indicate that the mean years of experience of employees is lower than 8.7? QUESTION 8 To determine the average weight of carryaon luggage by passengers in airplanes, a sample of 44 pieces of carry-on luggage was weighed. The average weight was 23 pounds. Assume that we know the standard deviation of the population to be 9 pounds. Determine a 97% confidence interval estimate for the mean weight of the carry-on luggage. Provide the lower limit of the confidence interval. QU ESTION 9 A random sample of 20 students at a university showed an average age of 20.1 years and a sample standard deviation of 2.3 years. The 93% confidence interval for the true average age of all students in the university is? Enter in the upper limit of your confidence interval. QU ESTION 1 0 A random sample of 899 people was taken. 203 of the people in the sample favored Candidate A. Find 90% confidence interval for the true proportion of people who favors Candidate A. Enter in the lower i:_a an n... -2azzaaaaa 114_.~I-.'..1_...'J