# Dunder Data Challenge #2 — Explain the 1,000x Speed Difference when taking the Mean

Published in

8 min readApr 16, 2019

This is the second edition of the **Dunder Data Challenge** series designed to help you learn python, data science, and machine learning. Begin working on any of the challenges directly in a Jupyter Notebook thanks to Binder (mybinder.org).

In this challenge, your goal is to explain why taking the mean of the following…