Chapter 12.1, Problem 18AYU

Racial Profiling On January 1, 2004, it became mandatory for all police departments in Illinois to record data pertaining to race from every traffic stop. Mundelein, Illinois, has been collecting data since 2000. Rather than using census data to determine the racial distribution of the village, they thought it better to use data based on who is using the roads in Mundelein. So they collected data on at-fault drivers involved in car accidents in the village (the implicit assumption here is that race is independent of fault in a crash) and obtained the following distribution of race for users of roads in Mundelein.

The following data represent the races of all 9868 drivers who were stopped for a moving violation in the village of Mundelein in a recent year,

1. a. Does the distribution of race in traffic stops reflect the distribution of drivers in Mundelein? In other words, is there any evidence of racial profiling in Mundelein? Use the α = 0.05 level of significance.
2. b. Compare observed and expected counts for each category. What does this information tell you?