Answer:2.31
Step-by-step explanation: considering that the root of 3 has already been given. Will just divide 4 by the root of 3 which is 1.73. and the answer it gives is 2.31
Answer: 15 students
Step-by-step explanation:
From the question, we are informed that there are 150 students in 6th grade, and that 10% earned straight As last quarter.
The number of students that earned straight As will be:
= 10% × 150
= 10/100 × 150
= 0.1 × 150
= 15 students
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
πR³
