A researcher conducts a study of white and black attitudes toward the police in her community. The percentage of white respondents (N = 300) who say they have a favorable attitude toward the police is 55% with a 95% confidence interval of +/- 5.6%. The percentage of black respondents (N = 250) who say they have a favorable attitude toward the police is 41% +/- 6.1%. Is there a real difference between the percentage of whites and blacks who have a positive attitude toward the police in the larger population, or is this sample difference likely to have occurred by random chance or sampling error?