Section 1 - Basic Probability Concepts

Disclaimer This is just a quick overview; not everything STAT 414 does a great job teaching basic probability Make sure you read through Actex chapter 1 and understand all of the basic concepts I don’t want to waste time and be redundant this but these concepts form the foundation of everything – make sure you know it!

How to Study Basic Probability These are all “tools for your toolbox” Many of them seem obvious and basic, but RECALL is important Problems are written to see if you know all of the formulas – Be able to immediately recognize what formula a problem is based on – This is why it’s important to work problems!

Basic Probability Try to use venn diagrams (“common sense” over formula memorization) Look for complementary probabilities These are the “gimme” problems so get those easy points! Use visuals to lay out the problem Union: “or” Intersection: “and”

Some Terminology Mutually exclusive: Two events that have no intersection Independent: Two events such that the occurrence of one gives no information about the occurrence of the other (Think MULTIPLY!!!) – OPPOSITE of mutually exclusive: a mutually exclusive event tells you the other doesn’t occur Partition: Events form a “partition” of the probability space if they take up the whole space (aka Exhaustive) – Or, events form a “partition” of another event if they take up the whole event – (This is important to understand for Bayes Theorem)