X ~ B(n, p)
n: number of trials
p: probability of success
The binomial distribution is a discrete distribution used to calculate
the probability of a given number of successful outcomes (x) from a fixed number of trials (n).
Example
B(4,0.4): The probability of success is 0.4 for each trial and there are 4 trials
Conditions
- The number of trials is fixed
- The trials are independent of each other
- There are two possible outcomes; success or failure
- The probability of success is constant
Formulae
x: The number of successful outcomes.
|
| × px(1 - p)n-x |
E(X) = np |
VAR(X) = np(1 - p) |