The Negative Binomial Distribution is used for modeling rates of occurrence.
The Negative Binomial distribution has two parameters:
- r = the total number of failures.
- = P("success").
A process that manufactures widgets is monitored.
As each widget exits the process line, it is tested for defective versus non-defective.
On the fifth defect, the process is stopped for re-adjustment.
The random variable X follows a Negative Binomial distribution with r = 5 and = P(widget is non-defective).