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:
y= 3x
Step-by-step explanation:
This is honestly your basic times tables if we are being honest. We know that she read 3 paragraphs per minute. We also know that in 4 minutes, she read 12 paragraphs. 4 times 3 = 12. So the answer is y=3x.
Answer:
the first
Step-by-step explanation:
yes
I believe it is 66 miles per hour
