Question
Questton 21ptsAbank manager has developed new system to reduce the time customers spend wraiting to be served by tellers during peak business hours. The mean waiting time during [ peak business hours under the current system is roughly 9 to 10 minutes The bank manager hopes that the new system will have mean waiting time that is less than six minutes The mean of a sample of 100 bank customer waiting times in is 5.46. The population standard deviation of waiting times is 2.47.What is the upper co
Questton 2 1pts Abank manager has developed new system to reduce the time customers spend wraiting to be served by tellers during peak business hours. The mean waiting time during [ peak business hours under the current system is roughly 9 to 10 minutes The bank manager hopes that the new system will have mean waiting time that is less than six minutes The mean of a sample of 100 bank customer waiting times in is 5.46. The population standard deviation of waiting times is 2.47. What is the upper confidence limit of the 90% confidence interval for the mean waiting time Include 2 decimal places in your answer: Question 3 1pts Aquality control engineer is interested in the mean length of sheet insulation being cut automatically by machinc The desired mean length of the insulation is 12 feet It is known that the standard deviation in the cutting length is 0.15 feet: sample of 35 cut sheets vields mean length of 12.14 fcet What is the lowcr confdence limit of the 99% confidence intenval for the average length? Include decimal places in vour answer:


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A researcher for the FAA wants to estimate the average flight time (in minutes) from Albuquerque, New Mexico, to Dallas, Texas, for flights with American Airlines. He randomly selects nine flights between the two cities and obtains the data shown. Assume that $\sigma=8$ minutes. (TABLE CAN'T COPY) (a) Use the data to compute a point estimate for the population mean flight time between Albuquerque and Dallas on an American Airlines flight. (b) Because the sample size is small, we must verify that flight time is approximately normally distributed and that the sample does not contain any outliers. The normal probability plot and boxplot are shown next. Are the conditions for constructing a $Z$ -interval satisfied? (FIGURE CAN'T COPY) (c) Construct a $95 \%$ confidence interval for the flight time. Interpret this interval. (d) Construct a $90 \%$ confidence interval for the flight time. Interpret this interval. (e) What happened to the width of the interval when the level of confidence decreased? Explain why this result is reasonable.