With the high cost of fuel, airlines are trying many things to save money. continental is using smaller planes on its nonstop flights from northern europe to the eastern united states. as a consequence, when there is a strong headwind, these flights use more fuel than usual. a greater proportion of these nonstop flights are of necessity, stopping for fuel. it is reported that in december 2011, continental had to stop for fuel on 43 out of 1100 flights. one year earlier, when continental was using a larger plane for this route, they only stopped for fuel on 12 of the 1100 flights.

a)are these proportions from matched-pairs data? explain your answer.

b)what is the result of the appropriate hypothesis test, using ? = 0.05 level of significance? (note: list out each step in your hypothesis testing procedure and show all of your work.)

step 1:

step 2:

step 3:

step 4:

step 5:

c)do you think that there is a practical difference in the proportion of flights that stop for fuel in december 2011 compared to the previous year? explain your answer.

d)construct a 95% confidence interval for the difference between the proportion of nonstop flights that stopped for fuel in december 2011 and the proportion of flights using the larger plan the year earlier.

lower bound:

upper bound: