A probability is the likelihood that a particular event will occur. We all use probabilistic reasoning every day. If I buy a lottery ticket, what are my chances of winning? What is the likelihood that I will get a promotion if I put in extra effort at work? What is the probability that I will get pulled over if I drive 5 miles per hour over the speed limit? These musings involve predictions about the likelihood that a certain event will (or will not) occur. We use past experiences and what we know (or what we assume to be true) about the world to inform our judgments about the chance of occurrence.

Probability: The likelihood that a certain event will occur.

Don't use plagiarized sources. Get Your Custom Essay on
Just from $13/Page
Order Essay

Probabilities are linked intricately with proportions; in fact, the probability formula is a spinoff of Formula 3(1). Flip back to this formula right now for a refresher. Let us call a particular event of interest A. Events are phenomena of interest that are being studied. The probability that event A will occur can be symbolized as p (A) (pronounced “p of A ”) and written formulaically as

Coin flips are a classic example of probabilities. Any two-sided, fair coin will land on either heads or tails when flipped, so the denominator in the probability formula is 2 (i.e., there are two possible outcomes of the coin flip).


and taste our undisputed quality.