C
n
x
n x
x p q − is the (x + 1)th term in the binomial
expansion of (q + p)n Thus, the probability distribution of number of successes in an experiment consisting
of n Bernoulli trials may be obtained by the binomial expansion of (q + p)n Hence, this
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PROBABILITY      575
distribution of number of successes X can be written as
X
0
1
2 x