Weighted Least Squares Slope Estimate

Problem

The weighted least squares slope is sum(w_i (x_i - xbar_w)(y_i - ybar_w)) / sum(w_i (x_i - xbar_w)^2), where the weighted means use the same weights.

Given the predictor values, responses, and weights, return the slope.

Hint

Center both variables with weighted means before the ratio.

case 1

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

expected: 2

case 2

in: [[0,1,2],[1,1,3],[1,2,1]]

expected: 1

case 3

in: [[1,2],[3,5],[2,3]]

expected: 2

Starter codePython

def weighted_least_squares_slope(xs, ys, weights):
    # Your code here
    pass

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