The theoretical probability is what is expected to happen which is 0.25 or 25%. The experimental probability is the actual or observed during the play. Since the person won half of 20 games, the experimental probability is 10/20 or 50%.
The difference between the theoretical and experimental probability is then
50%-25%=25% or 0.25
We note that the experimental probability is higher than the theoretical. However, as more games are played, the fraction of games won becomes closer and closer to the theoretical probability.
