2.8. A public opinion poll of 471 randomly selected adult respondents asked about their views on the treatment of offenders by the courts. Expecting race/ethnicity to be related to views about the courts, a researcher classifies respondents as African American, Hispanic, and white. To test for the effect of race/ethnicity, he computes one regression using information about the age, sex, income, and education of the respondents and finds the R2 for this model to be 0.11. In a second regression, he adds two dummy variables for African American and Hispanic, using white as the reference category. The R2 for this second model is 0.16. Explain whether the race/ethnicity of the respondent had a statistically significant effect on views about the courts (assume a 5% significance level).