BA275 FNDS OF STATISTICAL INFERENCE

Part I:

*Open your data in Excel or Statgraphics and answer the following in complete sentences. Use for each of the below tests.

1) Do different airlines have different on-time performances? Choose a set of 30 flights from 4 carriers (120 data points all together) at random and calculate an ANOVA test of multiple means for the effect of carrier code on departure delay.

2) Give your conclusion in statistical terms. What is the null hypothesis? Do we reject it? Why or why not?

3) Give your conclusion in everyday terms. Should I pay attention to which airline I’m flying, if I care about the delay in departure? Why or why not?

Part II:

1) Is departure delay predictive of arrival delay? Choose 40 flights at random and perform a simple linear regression. Include your Statgraphics or Excel output (ANOVA table and Coefficients table)

2) Based on the information above, in your own words: do you believe that departure day is predictive of arrival delay? Why or why not?

3) Give your best guess about the change in arrival delay when departure delay increases by one minute. Justify your answer using your results above.

4) Two options for question 4: either give practical advice to travelers based on your conclusions above, OR suggest a different simple linear regression you could perform on this data which would yield practical advice for travelers.