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:
no solution
Step-by-step explanation:
-4(x+5)=-4x-30
-4x-20=-4x+30
no solution
x cancel
Answer:
a = - 27
Step-by-step explanation:
-
a - 6 = 12 ( add 6 to both sides )
-
a = 18 ( multiply both sides by 3 to clear the fraction )
- 2a = 54 ( divide both sides by - 2 )
a = - 27
Answer: The height of the tree is 27f
t
Step-by-step explanation: We can set up a proportion comparing the height of each object to the length of the shadow.
h/s
h/15=18/10
Cross multiply
10.h= 18*15
10h=270
Use the multiplicative Inverse
10
h/
10
=
<em><u>270
/10
=27</u></em>
Answer:
1. (0,0) (3,1) (6,2)
2. proportinal
3. im so sorry but i cant see that one i really am sorry!
Step-by-step explanation:
i hope i helped brainliest?