Probability is the measure of the likelihood that an event will occur. Probability is quantified as a number between 0 and 1 (where 0 indicates impossibility and 1 indicates certainty). The higher the probability of an event, the more certain we are that the event will occur.

Try This:

Sometimes in life, people use patterns to try and predict what will happen in the future. It is referred to as the probability of something happening. In this lesson, you will learn about simple probability.

Now let's take a look at some examples using the Northern Alberta Volleyball Club from the previous activity.

The NAVC has won four out of their last five games. We can figure out the probability of them winning their next game like this:

P(winning)     =     4
                                     5

Convert the fraction to a decimal using division (4/5).

P(winning) = 0.8, or 80%

The probability of winning their next game based on their previous five games is 80%. Notice that the word you are trying to figure out, the probability of winning, is written in brackets behind the letter P, which represents the word probability.

Once you have found out the probability of something occurring, you can also find out the probability of something not occurring. You do this by subtracting the probability of something occurring from 1. The number 1 represents a 100% chance of something occurring.

To calculate the chance of NAVC losing their next game, you would use the formula :

P(winning)     =     1 – P(winning)
      =     1 – 0.8
      =     0.2, or 20%

There is a 20% chance of NAVC not winning their next game!

  Self-check!