In the September issue, we saw that a lower proportion of Hispanics and blacks take physics in U.S. high schools than do whites and Asians. Last month, we examined physics offerings and students by socioeconomic profile of the high school as reported by the principal. We saw that there were more physics classes and more physics students at better-off high schools. These increased offerings allow the teachers who teach physics to focus more on physics. We combined race and ethnicity data from the National Center for Education Statistics with data from our principals to examine the percent of each race and ethnicity attending schools by our socioeconomic profile of the school. Less than one-third of white and Asian public high school students attend a school that our principals classify as "worse off." Less than one-fourth of black and Hispanic students attend a school that our principals classify as "better off." The difference is stark. When combined with the percent of physics classes and physics students at each type of school, we have some insight into explaining the variation in physics taking by race and ethnicity. (Contains 1 figure.)