In terms of the parameters of the probability mass function, what is the formula for the standard deviation of a Poisson distribution? Statistics Random Variables Probability Distribution 1 Answer Chandra S. Oct 21, 2015 f (x ) = # e ^- m# #m ^x# / x !, x = 0, 1, 2 ... #oo# is the p.d.f. of Poisson distribution. Its variance is 'm' , the parameter in the p.d.f. and hence S.D = #sqrt#m. Answer link Related questions What is the difference between a discrete random variable and a continuous random variable? What is the sum of the probabilities in a probability distribution? What is an example of a continuous random variable? How are random variables generally identified (i.e., what notation is used to identify a random... What does the term "expected value" mean? What notation is used to designate the expected value of a random variable? You roll three dice, and you define the random variable #X# as the number of heads obtained. ... You have studied the number of people waiting in line at your bank on Friday afternoon at 3 pm... You have studied the number of people waiting in line at your bank on Friday afternoon at 3 pm... You have studied the number of people waiting in line at your bank on Friday afternoon at 3 pm... See all questions in Probability Distribution Impact of this question 2926 views around the world You can reuse this answer Creative Commons License