MCQ 11 Mark
The p.m.f. of a r.v. X is
P(x) = `{{:((2x)/(n(n + 1))"," x = 1"," 2"," ...."," "n"),(0"," "otherwise"):}` Then, E(X) = ______.
- ✓`(2n+1)/3`
- B`(n+2)/3`
- C`(2n-1)/3`
- D`(n+1)/3`
Answer
View full question & answer→Correct option: A.
`(2n+1)/3`
A