Question
A class has 15 students whose ages are 14, 17, 15, 14, 21, 17, 19, 20, 16, 18, 20, 17, 16, 19, 20 years. One student is selected in such a manner that each has the same chance of being chosen and the age X of the selected student is recorded. What is the probability distribution of the random variable X ? Find mean, variance and standard deviation of X.
Solution
Table
|
Age X |
Frequency |
|
14 |
2 |
|
15 |
1 |
|
16 |
2 |
|
17 |
3 |
|
18 |
1 |
|
19 |
2 |
|
20 |
3 |
|
21 |
1 |
Probability Distribution Table
Mean X = 
Variance X = 
