For the cities described in Exercise 2.53,
a. Construct a simple tabulation in which the counts are according to the grade on personnel policies.
b. Construct a cross-tabulation describing the cities, using the grade on personnel policies and the grade on managing for results as the categorization variables.
c. Construct a display showing the average population according to grade on personnel policies and the grade on managing for results. Do the categorization variables seem to be related to the level of population? If so, how?