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CBSE Class 12-science Answered

A bag contains 4 black and 3 red balls. Let X be the random variable of red balls. Find the mean and variance of the random variable X, if three balls drawn successfully with replacement.
Asked by Topperlearning User | 04 Jun, 2014, 01:23: PM
answered-by-expert Expert Answer

Let X be the random variable denoting the number of red balls. Then X can take values 0, 1, 2 & 3.

p = probability of getting a red ball = 3/7 and q = 1 – p = 4/7
 
X or xi
0
1
2
3
P(X) or pi
 
Answered by | 04 Jun, 2014, 03:23: PM

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