Answer:
6
Step-by-step explanation:
Substitute n for 3
A(n) = 3/2(-2)^(n-1)
A(3) = 3/2(-2)^(3-1)
A(3) = 3/2(-2)²
A(3) = 3/2(4)
A(3) = 12/2
A(3) = 6
Answer:
A. E(x) = 1/n×n(n+1)/2
B. E(x²) = 1/n
Step-by-step explanation:
The n candidates for a job have been ranked 1,2,3....n. Let x be the rank of a randomly selected candidate. Therefore, the PMF of X is given as
P(x) = {1/n, x = 1,2...n}
Therefore,
Expectation of X
E(x) = summation {xP(×)}
= summation {X×1/n}
= 1/n summation{x}
= 1/n×n(n+1)/2
= n+1/2
Thus, E(x) = 1/n×n(n+1)/2
Value of E(x²)
E(x²) = summation {x²P(×)}
= summation{x²×1/n}
= 1/n
Answer:
A
Step-by-step explanation:
