Sample Space
The probability range defines the mathematical boundaries within which the likelihood of any event must fall. According to theoretical probability, the probability of an event always lies between 0 and 1, inclusive. This means the value can never be negative or exceed 1.
Key Concepts
The probability of an impossible event is exactly 0, meaning it cannot happen under any circumstances.
The probability of a sure event is exactly 1, meaning it is absolutely certain to happen.
Any probability value can be expressed as a fraction, a decimal between 0 and 1, or a percentage ranging from 0% to 100%.
The sum of the probabilities of all elementary events of a random experiment is always exactly 1.
Real World Applications
When tossing a standard coin, the probability of getting a head is 0.5, which falls perfectly in the middle of the 0 to 1 range.
A weather forecast predicting a 70% chance of rain translates to a probability of 0.7, which is within the valid mathematical range.
The probability of rolling an 8 on a standard six-sided die is 0, representing an impossible event at the lowest end of the probability range.