Find Standard Deviation from Given mean

Hey,

Can we find Standard deviation of a distribution if we have the mean of the distribution?

[Image Analyst]

Of course not. You'd need the distribution itself, or at least some samples from the distribution.

[Rithwik Goud Salloori]

What if it is a Uniform Distribution or Lognormal distribution?

[Jeff Miller]

No, neither of those distributions. It is only possible for a few special 1-parameter distributions like the exponential and the Poisson. (Maybe only those two--I don't know of another.)