# why has author divided by 1.5 in hands on machine learning with scikit learn

I am reading Hands-On Machine Learning with Scikit-Learn and TensorFlow (76/718), and the author is talking about dividing the dataset into a test set which i follow, but then goes on to talk about strata with this test set, and divides median household income by 1.5.

Can anyone help out as to why he has divided by 1.5 it is really bugging me because he has not explained it! I would really appreciate it :)

• The author explain it: "to limit the number of income categories". Have you tried removing the 1.5 factor ? what did it do ? – Lcrmorin Feb 11 at 13:32