
Explanation:
The correct answer is B: 23.43
Covariance between two random variables (Company A profits) and (Company B profits) is given by:
You are given .
takes values: -1, 0, 2, 4 (in millions).
Using the joint probability table:
This yields:
million
takes values: -50, 0, 10, 100 (in millions).
This yields:
million
Rounded to two decimal places, this is 23.43.
(Note: The joint probabilities sum to approximately 1.0005 due to minor rounding in the table, but this has negligible impact on the final result.)
This matches option B exactly.
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Q.3747 The yearly profits of the two firms A and B can be summarized in the following probability matrix.
| Company A (X₁) Profits | |||||
|---|---|---|---|---|---|
| -1 Million | 0 Million | 2 Million | 4 Million | ||
| Company B (X₂) Profits | -50 Million | 0.0197 | 0.0395 | 0.010 | 0.002 |
| 0 Million | 0.0390 | 0.230 | 0.124 | 0.0298 | |
| 10 Million | 0.011 | 0.127 | 0.144 | 0.0662 | |
| 100 Million | 0 | 0.0309 | 0.0656 | 0.0618 |
What is the covariance of company A and B given that E(X₁X₂) = 43.23?
A
24.56
B
23.43
C
21.45
D
22.45