Kind of confused how I should set this up. Police officer feels 20% of his employees did a horrible job. If failure is correct, then the probability is 73 are from 30 to 40 will be due to the failure.

then the probability is 73 are from 30 to 40 will be due to the failure.

I am sorry, but this makes no sense. Please rephrase.

Could you try to type in a clear language please? Your questions are more and more difficult to understand.