Mathematics Stack Exchange is a question and answer site for people studying math at any level and professionals in related fields. Join them; it only takes a minute:

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

If were told that something is gamma distributed with mean $m$, are we able to use that to find one of the parameters? Like if were told that something is exponentially distributed with mean $m$, then the it's exponentially distributed with parameter $\lambda =\frac1m$. Can we also do this with the gamma? (not necessarily put the mean in the denominator, but use this info to our advantage).

share|cite|improve this question
up vote 2 down vote accepted

No, because the mean is a function of both parameters. The best you can do is use $m$ to constrain the relation between the parameters, i.e. $m\beta=\alpha$. To determine one (and therefore both) of the parameters you'll need another measure, for example the variance.

share|cite|improve this answer

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.