Let x be a discrete random variable whose probability distribution is defined as follows:

P(X=x)=k/2ˣ​

where k is a constant. Calculate:

(i) The value of k

(ii) E(X), the expected value of x

a) k=2,E(X)=2

b) k=1,E(X)=1

c) k=2,E(X)=1

d) k=1,E(X)=2