Step 1: For each group, calculate the selection ratio - this is the number of applicants who passed the selection device divided by number of applicants who took it.

Step 2: Identify the group with the most advantageous selection rate (i.e., the group with the greatest percentage of people who passed the test), and multiply that selection rate by 80%. Do the selection rates for the other group(s) equal or exceed 80% of the most advantaged group? If so, then there is no adverse impact. If not, then there is adverse impact against the groups whose selection rates were lower than that threshold.