Question 1023359
 
Question:
Find the mean and standard deviation of x for binomial probability distribution with n=100 and p=0.3? 
 
Solution:
The mean (μ) and standard deviation (σ) of the given distribution can be found according to standard formulae:
Mean (μ) = np
Standard Deviation (σ) = √(npq)
where n=number of Bernoulli steps in the experiment,
p=probability of success
q=(1-p)=probability of failure.
 
For the given problem, 
n=100
p=0.3
q=(1-0.3)=0.7
therefore 
mean=np=100*0.3=70
standard deviation=√(npq)
=√(100*0.3*0.7)
=√(21)
=4.583 (approximately)