In order to explore if there is a difference in the proportion of students with a score greater than the average mean scale score for the subject of Mathematics across different ethnicities (Asian, Hispanic, Black, White) for schools having outlets with lead content > 15 ppb. I used a chi square test for this purpose.
H0 : There is no difference in the proportion of the various ethnicities of the schools having >15 ppb high lead level in water outlets with mean scale score greater than the average mean scale score for these schools.
H1 : There is a difference in the proportion of the various ethnicities of the schools having >15 ppb high lead level in water outlets with mean scale score greater than the average mean scale score for these schools.
Significance level : alpha = 0.05