Stats CH 4-4.3 Complements, Conditional Probability

"At least one" is equivalent to "one or more." The complement of getting at least one item of a particular type is that you get no items of that type.

Let A = getting at least one of some event Then ^A = getting none of the event being considered Find P(^A) = probability that event A does not occur Subtract the result from 1: P = 1 - P (no occurrences of event A)

of an event is a probability obtained with the additional information that some other event has already occurred. Intuitive Approach For Finding: P (B|A) This denotes the conditional probability of event B occurring, given that event A has already occurred. Formal Approach for Finding Conditional Probability: P (B|A) = P (A and B) / P (A) (found by dividing the probability of events A and B both occurring by the probability of event A)

the probability that an event will occur before obtaining additional evidence regarding its occurrence

A probability that is a revision of a prior probability using additional information.