## Quick Reference

The continuous probability distribution with probability density function *f* given by *f*(*x*)=λ exp(−λ *x*), where λ is a positive parameter, and *x*≥0. It has mean 1/λ and variance 1/λ^{2}. The time between events that occur randomly but at a constant rate has an exponential distribution. The distribution is skewed to the right. The following figure shows the probability density function of the exponential distribution with λ=10.

*Subjects:*
Mathematics.