Q10 of 108 Page 271

A discrete random variable X has the probability distribution given as below:


(i) Find the value of k


(ii) Determine the mean of the distribution.

Given table—



(i) We know that , where pi ≥0


P1+ P2+ P3+ P4 = 1


k+ k2+2k2+ k = 1


3k2 + 2k -1= 0


3k2 + 3k- k- 1 = 0


3k(k+1) -1 (k+1) = 0



Since, k≥ 0, we take


(ii)


= 0.5(k)+ 1(k2) + 1.5(2k2) + 2(k)


= 4k2 + 2.5k





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