Probability
Probability is the likelihood of something happening in the future.
It is expressed as a number between zero (can never happen) to 1
(will always happen).
It can be expressed as a
fraction, a
decimal, or a
percent.
Here is a table of typical probabilities:
| EVENT |
Probability |
| as a fraction |
as a decimal |
as a percent |
| The sun rises in the morning | 1 | 1.0 | 100% |
| A flipped coins turns up 'heads' | 1/2 | 0.5 | 50% |
| A card drawn out of a deck is a club | 1/4 | 0.25 | 25% |
| A card drawn out of a deck is a spade, heart, or diamond |
3/4 | 0.75 | 75% |
| A kid flies by flapping her arms | 0 | 0. | 0% |
To learn more about probability, see the probability notes.
Here are a couple of problems for you:
- What is the probability of a birthday being on a Tuesday? _____
- What is the probability of drawing a red card out of a standard deck of 52 cards? _____
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