The four-fifth rule was established since the 1970s after different discriminatory practices were evidenced that had serious impacts on minority or vulnerable populations.
This rule dictates that a selection rate for any minority group that is less than four-fifths (80%) of the group with the highest rate is evidence of disparate impact.
Answer
Yes, there is evidence of disparate impact, as the selection rate for African American males is 10%, which represents 50% of the selection rate for white American males, which is 20%