A variable x has a binomial distribution with probability of success 0.65 for each trial. For a total of 50 trials, what are the mean and the standard deviation of the distribution?

Question

this has two different symbols in the answer but each one can be represented as either solution.

Answer 1

Standard Deviation (SD) = sqrt(npq) where n = # of trials = 50

p = probability of success = .65

q = probability of failure = .35

SD = sqrt(50*.65*.35) = 11.375

Mean = np = 50*.65 = 32.5