Thirty-seven percent of all Americans drink bottled water more than once a week (Natural resources Defense Council, December 4, 2015). Suppose you have been hired by he Natural Resources Defence Council to investigate bottled water consumption in St. Paul. You plan to select a sample of St. Paulites to estimate the proportion who drink ottled water more than once a week. Assume the population proportion of St. Paulites who drink bottled water more than once a week is 0.37, the same as the overall proportion of Americans who drink bottled water more than once a week. Use z-table. a. Suppose you select a sample of 540 St.Paulites. Show the sampling distribution of p (to 4 decimals). E(p) = 0.3700 F = 0.0208 p. Based upon a sample of 540 st. Paulites, what is the probability that the sample proportion will be within 0.01 of the population proportion (to 4 decimals). probability = 1.0000 . Suppose you select a sample of 200 St.Paulites. Show the sampling distribution of p (to 4 decimals). E(p) = 0.3700 F = 0.6083 d. Based upon a smaller sample of only 200 St. Paulites, what is the probability that the sample proportion will be within 0.01 of the population proportion (to 4 decimals). probability = 0.0279

Researchers at Purdue University and Wichita State University found that airlines are doing a better job of getting passengers to their destinations on time.t AirTran Airways and Southwest Airlines were among the leaders in on-time arrivals with both having 88% of their flights arriving on time. But for the 12% of flights that were delayed, how many minutes were these flights late? Sample data showing the number of minutes that delayed flights were late are provided in the file named AirDelay. Data are shown for both airlines. Assume population variances are unknown and unequal. AirTran Southwest 34 59 | 43 30 3 45 64 42 33 66 32 42 | 85 30 48 105 45 28 | 38 85 110 50 10 33 50 26 70 75 45 63 52 83 78 27 70 42 35 33 64 65 27 90 38 52 76 (a) Formulate the hypotheses that can be used to test for a difference between the population mean minutes late for delayed flights by these two airlines. (Let u, = population mean minutes late for delayed Airtran flights and u, = population mean minutes…

Suppose an internet marketing company wants to determine the current percentage of customers who click on ads on their smartphones. How many customers should the company survey in order to be 90% confident that the estimated proportion is within five percentage points of the true population proportion of customers who click on ads on their smartphones?

According to an article in Newsweek, the natural ratio of girls to boys is  100:105 . In China, the birth ratio is  100:116  ( 46.3%  girls). Suppose you don’t believe the reported figures of the percent of girls born in China. You conduct a study. In this study, you count the number of girls and boys born in  100  randomly chosen recent births. There are  42  girls and  58  boys born of the  100 . Based on your study, do you believe that the percent of girls born in China is  46.3 ? A.)What is the test statistic?    Round your answer to three decimal places. (z / t ) =  B.) What is the  p -value? Round your answers to four decimal places. p -value  = C.) Let  α=0.05 .      Decision: (Reject the null hypothesis / do not reject the null hypothesis)       Reason for decision: ( a < p-value / a > p-value)       Conclusion: There is (insufficient/ insufficient)  evidence to conclude that the percentage of girls born in China is different from  46.3% .