Question

Find k, such that the function  P(x)=k(4/x) ;x=0,1,2,3,4 k>0

                                                 =0 ,otherwise

Answer 1

P(x)=k(4/x) ;x=0,1,2,3,4 k>0

      =0 ,otherwise

`P(X = 0) = k^4C_0 = k(1) = k`

`P(X = 1) = k^4C_1 = k(4) = 4k`

`P(X = 2) = k^4C_2 = k(6) = 6k `

`P(X = 3) = k^4C_3 = k(4) = 4k`

`P(X = 4) = k^4C_4 = k(1) = k`

X	0	1	2	3	4
P(X = x):	k	4k	6k	4k	k

Since, the function represents a p.m.f.

`sum_(x=0)^4P(X=x)=1`

k + 4k + 6k + 4k + k = 1
16k = 1

 k = 1/16