Ask HN: Data Science, ML, AI: Resources to build a good math foundation

I am an electrical engineer turned python dev planning to make a transition to AI / ML / Data Science. I am in no hurry and first, want to make sure my math fundamentals are right. What are the resources you have found useful to get started? I found these resources extremely useful. Highlights of Calculus (https://www.youtube.com/watch?v=X9t-u87df3o&list=PLBE9407EA64E2C318)

MIT 18.06 Linear Algebra, Spring 2005 (https://www.youtube.com/watch?v=ZK3O402wf1c&list=PL49CF3715CB9EF31D)

Probabilistic Systems Analysis and Applied Probability(https://www.youtube.com/watch?v=j9WZyLZCBzs&list=PLUl4u3cNGP61MdtwGTqZA0MreSaDybji8) Please suggest - Areas that of maths/statistics that I need to explore. - Good math/statistics resources to get started.