Answer:
2, 4 are the correct ones
Answer:
Table 1 is not a function because there are two y-values with the same x-values. Remember... y values can repeat but x values cannot repeat when their corresponding y values are different.
Table 2 is a function.
You would need to omit either (3,7) or (3,-2).
Please vote brainliest! Hope this helps, have a nice day.
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
