Summary of Probability Probability: Likelihood of an Event occurring 𝑃(𝐸) = #𝑡𝑖𝑚𝑒𝑠 𝑒𝑣𝑒𝑛𝑡 𝐸 𝑜𝑐𝑐𝑢𝑟𝑠 #𝑎𝑙𝑙 𝑝𝑜𝑠𝑠𝑖𝑏𝑙𝑒 𝑑𝑖𝑓𝑓𝑒𝑟𝑒𝑛𝑡 𝑒𝑣𝑒𝑛𝑡𝑠 Not P(E) is probability that P(E) will not occur. Not P(E)=1 – P(E) Mutually Exclusive events: Cannot happen at once P(A or B)=P(A) + P(B) Mutually Inclusive events: Can happen at the same time or they don’t affect each other if they happen at different times P(A and B)=P(A)*P(B) If there is a case where events are inclusive, then P(A or B)=P(A) + P(B) – P(A and B) Solving Probability Problems Step 1: Find the data Step 2: Set up the probability formula Step 3: Solve for x