Wiki/lesson thread: Lesson 3

Hi everyone,

I am currently taking this “Intro to machine learning” course. Currently I am in lesson 3 and have one doubt.
In the lecture, Jeremy has taken the standard deviation of each row, along all the estimators. Why are we doing it and how is it related to confidence interval?
Also can anyone please provide me the link for the notebook present in the video?

Why would lowering the min_sample_leaf increase the run time?