Variance of ATE Estimator

Problem

Return the variance of the difference-in-means ATE estimator, var_x/n_x + var_y/n_y, using unbiased sample variances. Return 0.0 when either sample has fewer than two values.

Hint

Add the two squared standard errors.

Test cases

case 1

in: [[1,2,3,4,5],[2,4,6,8,10]]

expected: 2.5

case 2

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

expected: 0.5

case 3

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

expected: 0

case 4

in: [[2,2],[2,2]]

expected: 0

case 5

in: [[1,2,3],[10,20,30]]

expected: 33.66666666666667

Starter codePython

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

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