The table shows the probability distribution of siblings of students in a high school with 1500 students. What is the expected value for the number of
siblings of a randomly chosen student?
Number of siblings
0
1
2
3
4
5
Probability
0.18
0.65
0.09
0.05
0.02
0.01
A. 1.08
B. 2.5
C. 1.11
D. 1.29

Option C

Step-by-step explanation:

Let X be a discrete random variable that counts the number of siblings a randomly selected student has. Then the expected value of X is defined as:

Where is the probability that a randomly selected student has siblings

With

So in this case we know that

#of siblings 0        1        2        3        4         5

probability 0.20 0.65 0.08  0.04  0.02  0.01

Therefore:

The answer is the option C.