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.
Formula & Equation
P(E) represents the theoretical probability of an event E occurring.
Common Misconceptions
Myth: Probability can be a negative number if an event is highly unlikely to happen.
Fact: Probability can never be negative. The absolute lowest value is 0, which represents an impossible event. Negative probability does not exist in standard mathematics.
Myth: You can have a probability greater than 1, such as being 200% sure about an outcome.
Fact: In mathematics, the maximum probability is 1, which is equivalent to 100%. A probability of 1 means the event is a sure event, and it cannot be more certain than that.
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.
Frequently Asked Questions
Can the probability of an event be 1.5?
No, the probability of an event cannot exceed 1. The range of probability is strictly from 0 to 1.
What does a probability of 0 indicate?
A probability of 0 indicates an impossible event, meaning there is absolutely no chance for the event to occur during the experiment.
Can probability be expressed as a negative fraction?
No, probability cannot be negative. It must always be a positive fraction, zero, or one.