04. Review of Discrete Probability
Nd787 C4 L1 A03 Review Of Discrete Probability V1
Summary of Terms
Sample Space - The set of all possible outcomes for a probabilistic trial. For the case of rolling a single die, the sample space would be \left { 1,2,3,4,5,6 \right }
Outcome / Event - One single possible result in the sample space. For example, rolling a 2.
Probability Distribution - A mapping of events to probabilities. For a discrete distribution we can use a table like the following for a fair die:
| Event | Probability |
|---|---|
| 1 | 1/6 |
| 2 | 1/6 |
| 3 | 1/6 |
| 4 | 1/6 |
| 5 | 1/6 |
| 6 | 1/6 |
Normalization - A probability is normalized when the probabilities sum to 1.0. Any mathematically correct distribution must be normalized, but un-normalized distributions can also be useful if we just want to compare relative probabilities.
Conditional Probability - The conditional probability p(A|B) gives the probability of event A given that event B has already occurred.
Random Variable - A random variable is a variable whose possible values are outcomes of some random phenomenon.