6.9 The 2000 census statistics for Alabama give the percentage changes in population between 1990 and 2000 for each of the 67 counties. These counties were divided into two mutually independent groups, rural and nonrural, according to population size of less than 25,000 in 2,000 or not.

Random samples of nine rural and seven nonrural counties gave the following data on percentage population change:

Rural 1.1, 21.7, 16.3, 11.3, 10.4, 7.0, 2.0, 1.9, 6.2 Nonrural 2.4, 9.9, 14.2, 18.4, 20.1, 23.1, 70.4 Use all of the methods of this chapter to test the null hypothesis of equal distributions.