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
The lengths of sides of a triangle have to satisfy the triangle inequality, which states that the sum of the two shorter sides must exceed the length of the third side.
Here 9+8=17 (not greater), so these segments do not form a triangle.
Answer:
8
Step-by-step explanation:
36/9=4
12-4=8
8 is your answer
Answer:
37/24
Step-by-step explanation:
For the first blank, the answer should be the total weight of the solution which is derived from adding 5 grams and 20 grams. The answer would be,
T = 5 + 20 = 25 grams
For the second blank, the % solution is derived by dividing the amount of salt initially by the total amount of the resulting solution. This is as shown below.
C = ((20 x 0.5) / 25) x (100%)
Simplifying,
C = 40%
Answers:
a. 25 grams
b. 40%
