CALCULATING RACIAL DISPARITY GRADE
Racial disparity grade was assigned based on the racial disparity rate. Racial Disparity was calculated using the exclusion rate. Exclusion rate is the combined total of out-of-school suspension and expulsions. The highest exclusion rate was divided by the lowest exclusion rate. For example, if the blacks had an exclusion rate of 6.3, Asian 7.8, white 2.3, Hispanic 3.1, then the racial disparity rate would be calculated by dividing the exclusion rate of Asian (7.8) by white (2.3); resulting in a racial disparity rate of 3.39. Racial disparity rate tells you how more likely one racial group will be excluded over another racial group. Consequently, in this example. Asians are 3.39 times more exclusions than whites.
Because zero cannot be divided into another number .1 was used to calculate a racial disparity rate where the denominator is zero. For example, if the blacks had an exclusion rate of 6.3, Asian 7.8, white 0, Hispanic 3.1, then the racial disparit y rate would be calculated by dividing the exclusion rate of Asian (7.8) by white (.1 instead of zero); resulting in a racial disparity rate of 78; that is, Asian are 78 times more excluisons than whites.
 The denominator of any fraction cannot have the value zero. If the denominator of a fraction is zero, the expression is not a legal fraction because it's overall value is undefined