Question

Over the past semester, you've collected the following data on the time it takes you to get to school by bus and by car:

• Bus:(15,10,7,13,14,9,8,12,15,10,13,13,8,10,12,11,14,11,9,12) • Car:(5,8,7,6,9,12,11,10,9,6,8,10,13,12,9,11,10,7)You want to know if there's a difference in the time it takes you to get to school by bus and by car.

A. Compute a 99% confidence interval for the difference between the time it takes you to get to school on the bus and the time it takes to go by car. Draw a conclusion about this difference based on this confidence interval usingH0 : (u-u2)= 0asyournull.(2points)

B. Construct the same confidence interval you did in part d, this time using your graphing calculator. Show what you do on your calculator, and what you put into your calculator, and give the confidence interval and degrees of freedom. (Hint: Go back to previous study materials for this unit if you need to review how to do this.)(2 points)

C. How is the interval computed on a calculator different from the interval computed by hand? Why is it different? In this case, would you come to a different conclusion for the hypothesis H0 : (u-u2)= 0 if you used the confidence interval generated by the calculator? (1 point)

Answer 1