EXAM 4A

A research meteorologist has been studying wind patterns over the Pacific Ocean. Based on these studies, a new route is proposed for commercial airlines going from Seattle to Honolulu. It is known that the old route has a mean flying time of 5.25 hours with a standard deviation of .6 hour. The airline obtained temporary permission to fly this route and found that the mean flying time of 36 flights was 4.9 hours. In order to permanently fly this route, the airline would have to pay $500,000. Management wants a .05 significance level.

What is the null hypothesis (1)

What is the alternative hypothesis (2)

Explain Type 1 and Type 2 error in terms of this study (2)

Sketch the curve and show the regions of acceptance and rejection (4)

What is your decision rule? (1)

 Compute your test statistic (3)

What is your conclusion? Explain your conclusion in simple nontechnical terms. (2)

Calculate the p-value and discus how it may or may not change your conclusions. (3)

In the past, fuel consumption of engines manufactured by a large airplane company averaged 5500 pounds for the first 15 seconds. A random sample of 8 engines was tested and the mean fuel consumption was 5880 pounds with a standard deviation of 250. At the .01 level of significance, test the claim that fuel consumption has changed.

What is the null hypothesis (1)

What is the alternative hypothesis (2)

Explain Type 1 and Type 2 error in terms of this study (2)

Sketch the curve and show the regions of acceptance and rejection (4)

What is your decision rule? (1)

Compute your test statistic (3)

What is your conclusion? Explain your conclusion in simple nontechnical terms. (2)

A customer has launched a complaint based on this sample however the airline company thinks that the significance level might be have set too high. Calculate the p-value and discuss how it may or may not change your conclusions. (3)

A hospital reported that the normal death rate for patients with extensive burns (more than 40% of skin area) has been significantly reduced by the use of new fluid plasma compresses. Before the new treatment the mortality rate for extensive burn patients was about 60%. Using the new compresses, the hospital found that only 40 out of 90 patients with extensive burns died. Use a 1% significance level.

What is the null hypothesis (1)

What is the alternative hypothesis (2)

Explain Type 1 and Type 2 error in terms of this study (2)

Sketch the curve and show the regions of acceptance and rejection (4)

What is your decision rule? (1)

Compute your test statistic (3)

What is your conclusion? Explain your conclusion in simple nontechnical terms. (2)

 key