Explanation

The covariance between two random variables X and Y is calculated using the formula:

$\text{Cov}[X, Y] = E[XY] - E[X]E[Y]$

Given:

• $E[X] = 3$
• $E[Y] = 4$
• $E[XY] = 11$

Substituting into the formula:

$\text{Cov}[X, Y] = 11 - (3 \times 4) = 11 - 12 = -1$

Therefore, the covariance is -1, which corresponds to option A.

Key Concept: Covariance measures the directional relationship between two random variables. A positive covariance indicates that the variables tend to move in the same direction, while a negative covariance indicates they tend to move in opposite directions.