I believe this has to do with theoretical and experimental probabilities.
Experimental probabilities are what actually happens and theoretical probabilities are what is expected to happen.
A coin landing on tails 8 out of 10 times....this is experimental probability results based on an experiment....this is experimental probability outcomes that should happen....this is theoretical probability rolling a sum of 9 in 5 trials....this is experimental probability
so the one that is the odd ball is : outcomes that should happen
