Hidden Markov Models, Markov Chains.
there is 0.45 (45%) chance to golf, 0.2 (20%) chance to do boxing and 0.35 (35%) chance to play football. If it is Rainy then there is 0.2 (20%) chance to golf, 0.5 (50%) chance to do boxing and 0.3 (30%) chance to play football. This example HMM is a weather model, based on the activities