Function variance

maths/joint_probability_distribution.py:41–48

>>> from math import isclose >>> isclose(variance([1,2],[0.7,0.3]), 0.21) True

(values: list[int], probabilities: list[float])

# Function to calculate the variance
def variance(values: list[int], probabilities: list[float]) -> float:
    """
    >>> from math import isclose
    >>> isclose(variance([1,2],[0.7,0.3]), 0.21)
    True
    """
    mean = expectation(values, probabilities)
    return sum((x - mean) ** 2 * p for x, p in zip(values, probabilities))


# Function to calculate the covariance