Study Guide STA 013 EXAM #2 PDF

Bayes' Rule Expansion of the Conditional Probability Rule Typically used when we want to find P(B|A) and know P(A|B) Probability Trees are helpful visual tool for displaying probabilities that happen in stages. ​ Random Variable (RV) Variables whose values are numerical results from a random experim...

Bayes' Rule Expansion of the Conditional Probability Rule Typically used when we want to find P(B|A) and know P(A|B) Probability Trees are helpful visual tool for displaying probabilities that happen in stages. ​ Random Variable (RV) Variables whose values are numerical results from a random experiment. Discrete random variables can be summarized by a probability distribution. A distribution is valid if: all probabilities sum to 1. probabilities are values between 0 and 1. Center and Spread of a Probability Distribution Center: The center of a probability distribution is measured by it's mean, or Expected Value. Interpreted as the long run average It is a weighted average Spread: The spread of a probability distribution is measured by it's variance or standard deviation. Interpreted as the typical (long run average) distance between that value of the RV and the mean of X Binomial Distribution Named discrete probability distribution Four requirements n trials trials are independent two outcomes: "success" or "failure" probability of success, p, is constant Binomial RV, X, represents the number of successes out of n trials, where x= 0,1,2,....,n.