Probability_#52 closed

Question

Consider the following probability mass function of a random variable X

$p(X,q)=\{q\,\,if\,X=0 \\\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,1-q\,\,\,if\,X=1\\ 0\,\,otherwise$

If q=0.4, the variance of X is.?

Comments

Is it 0.24?

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@goxul how u arrived at 0.24?

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@Shubhanshu I just used the formula that $\sigma = E[X^2] - (E[X])^2$

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the answer is 0.56

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@Ayush Upadhyaya what is the right answer of this question?

i am getting 0.24 as 0.6-0.36=0.24