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
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Since, k≥ 0, we take ![]()
(ii) ![]()
= 0.5(k)+ 1(k2) + 1.5(2k2) + 2(k)
= 4k2 + 2.5k
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