SOLUTION: A discrete random variable X has probability mass function P(x) = a(2/5)^x, x=0,1,2,3... Find the value of a.
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Question 1189201: A discrete random variable X has probability mass function P(x) = a(2/5)^x, x=0,1,2,3... Find the value of a. Answer by ikleyn(52794) (Show Source):
The sum of the infinite geometric progression P(0) + P(1) + P(2) + . . . must be equal to 1. It gives an equation to find "a".
The sum is equal to = = .
So, must be equal to 1
= 1,
which gives a = = 0.6. ANSWER
