What are the mean and standard deviation of a binomial probability distribution with #n=210 # and #p=12/21 #?

1 Answer
Shwetank Mauria · Leland Adriano Alejandro
Mar 27, 2016

Mean is #120# and Standard Deviation is #7.171#

Explanation:

Binomial distribution is a frequency distribution of possible number of successful outcomes in given number of trials #n#, in each of which there is the probability of success is #p# (and #q=1-p# is probability of failure).

The mean and standard deviation of a binomial distribution are given by #np# and #sqrt(npq)#.

Here #n=210#, #p=12/21# and #q=1-12/21=9/21#.

Hence Mean is #210xx12/21=120#

Standard Deviation is #sqrt(210xx12/21xx9/21)#

= #1/21xxsqrt22680=150.6/21=7.171#

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