Practice Homework #4 Name:____________________________ Please show your work. 1. You are interested in studying systemic racism in the United States, and gather data on 825 residential neighborhoods throughout the country. The two variables which interest you are the quality of the neighborhood (a composite measure of the neighborhood's noise, pollution, crime, available services, and open space) and the neighborhood's proportion of non-whites. Perform a hypothesis test at 99% confidence to see if the quality is significantly related to the racial composition of the neighborhood. Proportion nonwhite Low Medium High Total 56 117 156 329 89 78 34 201 231 45 19 295 376 240 209 825 Neighborhood quality Low Medium High Total 2. You are researching the relationship between union membership and salaries among public servants, so you gather the following data classifying 1,190 fire departments from around the country using stratified random sampling. Based on the data summarized below, perform a 2 test at 90% confidence to see if there is a significant relationship between salary and union status. Status Nonunion Union Total 364 98 462 162 187 349 123 256 379 649 541 1,190 Salary Low Medium High Total 3. You are interested in testing the effectiveness of abstinence-only sex education against competing programs for comprehensive sex education. You gather data on four different programs in a total of 20 school districts, and track the rate of sexual activity among highschoolers over many years using doctors' anonymous records. Test the hypothesis at 95% confidence that the type of program has an effect on sexual activity rates. Abstinence-only A 32 45 39 36 42 ANOVA Between groups Within groups Total Abstinence-only B 35 28 52 43 39 Sum of Squares (SS) Comprehensive A 36 40 33 47 38 37 df Mean Square (MS) Comprehensive B 45 34 42 35 F