In: Statistics and Probability
Assume the following joint probability distribution function where X1 and X2 are random variables denoting faulty components coming from supplier 1 and supplier 2, respectively, where a is a constant value.
| X1 | |||||
| 0 | 1 | 2 | 3 | ||
| X2 | 0 | 0.15 | 0.1 | 0.1 | 0.1 |
| 1 | a | 0.15 | 0.1 | 0 | |
| 2 | 0 | 0 | 0.1 | 0.1 | |
| 3 | 0 | 0 | 0 | 0.1 | |
The correlation between X1 and X2 is: