Simple linear regression

Imagine that you are working in a secret laboratory.

Your colleague build a linear regression model based on some secret data below.

The resulting model is as follows:

$$y = -1.85x + 21.25$$

Help your colleague to compute the sum of squares of deviations $\sum_{i=1}^5 e^2 = \sum_{i=1}^ 5(y - \hat{y})^2$ of the obtained model.

import numpy as np

x = np.array([1, 3, 5, 7, 9])
y = np.array([18, 17, 13, 8, 4])