For the time being, the air traffic control system in the United States is run by the federal government. Several groups disagree with this and would like to privatize the air traffic control system. Among the arguments given for privatization is that flight delays are much too common in the United States. A first step in deciding if, indeed, delays in the U.S. are "too common" might be to compare the flight delay information from the U.S. and other nations.

You have in front of you the following chart, which summarizes the information from three samples of flights from the past six weeks. One of the samples is composed of domestic U.S. flights, one is composed of domestic Canadian flights, and one is composed of domestic British flights. The information recorded for each flight is the time (in minutes) that the plane was late to the arrival gate. (If the plane was early, the time recorded was negative.)

Groups Sample Sample Sample size mean variance United States 250 19.1 90.3 Canada 216 16.3 104.8 Great Britain 246 18.4 98.9 Send data to calculator v Send data to Excel You perform a one-way, independent-samples ANOVA test to decide if there are differences in the mean flight delay times among the three countries. Such a test uses the following statistic. Variation between the samples F = Variation within the samples For the flight delay information you've been given F ~4.97. (a) Give the numerator degrees of freedom of this F statistic. X 5 ? (b) Give the denominator degrees of freedom of this F K statistic. (c) Using the 0.05 level of significance, can you conclude from your ANOVA test that there are Yes O No differences in the mean flight delay times among the three countries