Nepedia
Back to Discover
Fluent Reader
🔢

Probability

math Maturity 11-13 Vital Level 3 Next article →

Probability is a way to measure how likely an event is to happen. We use numbers to describe this chance. These numbers always fall between 0 and 1. A larger number means the event is more likely to occur. You might also see these numbers written as percentages from 0% to 100%.

probability vs odds
probability vs odds

Imagine flipping a fair coin. There are only two possible outcomes: heads or tails. Because the coin is fair, both sides have an equal chance. The probability for heads is 1/2, which is also 0.5 or 50%.

Dice Distribution (bar)
Dice Distribution (bar)

There are different ways to think about these numbers. Theoretical probability uses math to find answers in a perfect setting. For example, if you toss a coin twice, there are four possible results. You could get head-head, head-tail, tail-head, or tail-tail. The chance of getting head-head is 1 out of 4, or 25%.

Mutually Exclusive and Non-exclusive Probability Events
Mutually Exclusive and Non-exclusive Probability Events

Other people use empirical probability. This looks at what actually happens during real experiments. Some thinkers believe probability describes a physical state of affairs. Others believe it is just a measure of how much we believe something is true.

People have studied these patterns for a very long time. Early interest often came from people playing games of chance. In the sixteenth century, Gerolamo Cardano showed how to use ratios to find odds.

Cardano
Cardano

Later, in 1657, Christiaan Huygens wrote one of the first scientific books on the subject.

Christiaan Huygens-painting
Christiaan Huygens-painting

In the 1700s, mathematicians like Jakob Bernoulli and Abraham de Moivre helped make it a branch of math. Pierre-Simon Laplace also made big discoveries about errors in the late 1700s. These thinkers helped turn simple guesses into a real science.

Many famous scientists helped build this field with specific rules. Pierre-Simon Laplace proposed two laws of error in 1774 and 1778. One of these is known as the normal distribution or the Gauss law.

Bendixen - Carl Friedrich Gauß, 1828
Bendixen - Carl Friedrich Gauß, 1828

Even though it is named after Gauss, it was a very complex discovery. In 1906, Andrey Markov introduced Markov chains to the study. Finally, Andrey Kolmogorov developed the modern theory using measure theory in 1931. These steps allowed math to describe very complex systems accurately.

We use probability in many parts of our daily lives. Insurance companies use it to decide how much to charge for protection. Governments use these methods to make rules for the environment. Even people who trade goods use it to guess future prices. For example, a trader might guess how a conflict will change oil prices. This helps them make better decisions in a world full of uncertainty. Probability helps us find patterns in things that seem random.

436 words

Where will your curiosity go next?

Keep exploring at your chosen reading level.

🖼️ Images & Media (6)
File:Dice Distribution (bar).svg
Dice Distribution (bar).svg
File:Cardano.jpg
Cardano.jpg
File:Christiaan Huygens-painting.jpeg
Christiaan Huygens-painting.jpeg
File:Bendixen - Carl Friedrich Gauß, 1828.jpg
Bendixen - Carl Friedrich Gauß, 1828.jpg
File:probability vs odds.svg
probability vs odds.svg
File:Mutually Exclusive and Non-exclusive Probability Events.jpg
Mutually Exclusive and Non-exclusive...
More to explore

What is Nepedia?

A free, ad-free encyclopedia for children. Every article is written at five reading levels, so the same page works for a five-year-old and a fifteen-year-old — use the level switcher above to see this one change. No account needed to read.