Consider the game of rock-paper-scissors to be an experiment. In the long run, roommate A chooses rock 50% of the time, and roommate B chooses rock 63% of the time; roommate A selects paper 45% of the time, and roommate B selects paper 36% of the time; roommate A chooses scissors 5% of the time, and roommate B chooses scissors 1% of the time. (These choices are made randomly and independently of each other.) The probabilities were assigned using the: