Some commercial airplanes recirculate approximately 50% of the cabin air in order to increase fuel efficiency. The researchers studied 1098 airline passengers, among which some traveled on airplanes that recirculated air and others traveled on planes that did not recirculate air. Of the 517 passengers who flew on planes that did not recirculate air, 104 reported post-flight respiratory symptoms, while 112 of the 581 passengers on planes that did recirculate air reported such symptoms. Is there sufficient evidence to conclude that the proportion of passengers with post-flight respiratory symptoms differs for planes that do and do not recirculate air? Test the appropriate hypotheses using a = 0.05. You may assume that it is reasonable to regard these two samples as being independently selected and as representative of the two populations of interest. (Use a statistical computer package to calculate the P-value. Use Pao not recirculate - Pdo recirculate Round your test statistic to two decimal places and your P-value to four decimal places.) z= 0.56 P= 0.1921 Conclusion: Yes, there is sufficient evidence

Roy's Texaco wants to keep the price of its unleaded gasoline competitive with that of other stations in the area. Roy's is currently charging $1.29 per gallon. To check that the average price for this gasoline for all stations within 12-mile radius is higher than his price, Roy randomly samples the price of unleaded gasoline at ten stations located in this area. He obtains the following data for the price per gallon (in dollars): 1.7, 1.5, 2.6, 2.2, 2.4, 2.3, 2.6, 3.0, 1.4, 2.3 Set up appropriate hypotheses and test them using a significant level of .01.

The authors of a paper compared two different instruments for measuring a person's capacity for breathing out air. (This measurement is helpful in diagnosing various lung disorders.) The two instruments considered were a Wright peak flow meter and a mini-Wright peak flow meter. Seventeen people participated in the study, and for each person air flow was measured once using the Wright meter and once using the mini-Wright meter. The Wright meter is thought to provide a better measure of air flow, but the mini-Wright meter is easier to transport and to use. Use of the mini-Wright meter could be recommended as long as there is not convincing evidence that the mean reading for the mini-Wright meter is different from the mean reading for Wright meter. For purposes of this exercise, you can assume that it is reasonable to consider the 17 people who participated in this study as representative of the population of interest. Data values from this paper are given in the accompanying table.…

QUESTION 2 Researchers conducted two surveys about teens are their use of social media. The first survey asked a random sample of 800 U.S. teens about their use of Instagram. A second survey asked the same questions to a random sample of 2253 Canadian teens. In these two studies, 73% of U.S. teens and 88% of Canadian teens said that they use Instagram. Use these results to answer the following questions about the proportion of U.S. and Canadian teens that use Instagram. (Round to the nearest whole hundredth as needed). What is the difference between the proportion of U.S. teens and the proportion of Canadian teens? The standard error for these two samples is and the upper limit is Using a 99% confidence level, the lower limit is