Mean (Expected Value)
Variance
where .
Standard Deviation
Example: Find Mean and Variance
Find the mean and variance of:
| 0 | 1 | 2 | 3 | |
|---|---|---|---|---|
| 0.1 | 0.3 | 0.4 | 0.2 |
Properties of Mean
Properties of Variance
Example: Find Probability Distribution
Two coins are tossed. Let be the number of heads. Find the probability distribution of .