MediumStatisticsst-003

Covariance

Problem

Compute the population covariance of two equal-length lists x and y:

cov = sum((x_i - mean_x) * (y_i - mean_y)) / N

Hint

Positive when x and y move together; negative when they move opposite.

case 1

in: [[1,2,3,4],[2,4,6,8]]

expected: 2.5

case 2

in: [[1,2,3],[3,2,1]]

expected: -0.6666666666666666

case 3

in: [[1,2,3],[1,2,3]]

expected: 0.6666666666666666

Starter codePython

def covariance(x, y):
    # Your code here
    pass

3 test cases · run your code against them in the editor