Hypothesis Testing of Mean & Proportion

37.) A study found that in 2005, 12.5% of U.S. workers belonged to unions. Suppose a sample of 400 U.S. workers is collected in 2006 to determine whether union efforts to organize have increased union membership.

A.) Formulate the hypotheses that can be used to determine whether union membership increased in 2006

B.) If the sample results show that 52 of the workers belonged to unions, what is the p-value for your hypothesis test/

C.) At a=.05 what is your conclusion

41.) Speaking to a group of analysts in January 2006, a brokerage firm executive claims that at least 70% of investors are currently confident of meeting their investment objectives. A UBS Investor optimism Survey, conducted over the period January 2 to January 15, found that 67% of investors were confident of meeting their investment objectives.

a.) Formulate the hypotheses that can be used to test the validity of the brokerage firm executive's claim

b.) assume the UBS investor optimism survey collected information from 300 investors. What is the p-value for the hypothesis test?

c.) at a=.05, should the executive's claim be rejected?

43.) Eagle Outfitters is a chain of stores specializing in outdoor apparel and camping gear. They are considering a promotion that involves mailing discount coupons to all their credit card customers. This promotion will be considered a success if more than 10% of those receiving the coupons use them. Before going national with the promotion, coupons were sent to a sample of 100 credit card customers.

a.) develop hypotheses that can be used to test whether the population proportion of those who will use the coupons is sufficient to go national

b.) the file eagle contains the sample data. Develop a point estimate of the population proportion

c.) use a=.05 to conduct your hypothesis test. Should Eagle go national with the promotion?

53.) The U.s. Energy Administration reported that the mean price for a gallon of regular gasoline in the United States was $2.357. Data for a sample of regular gasoline prices at 50 service stations in the lower Atlantic states are contained in the data file name Gasoline. Conduct a hypothesis test to determine whether the mean price for a gallon of gasoline in the lower Atlantic states is different from the national mean. Use a=.05 for the level of significance and state your conclusion

55.) An Airline promotion to business travelers is based on the assumption that two thirds of business travelers use a laptop computer on overnight business trips.

a.) State the hypotheses that can be used to test the assumption

b.) What is the sample proportion from an American Express sponsored survey that found 355 of 546 business travelers use a laptop computer on overnight business trips?

c.) What is the p=value?

d.) Use a=.05. What is your conclusion?