If it has an adjustable rate, it must have reasonable annual and lifetime limits on rate increases and provide for the rate to be determined by the addition of a margin to an index rate based on a widely available index such as indices for US.

If you have no investment knowledge in the equities market, I would recommend buying the S&P Index 500 which will beat the performance of 80% of all fund managers over the long run.

They are usually tied to prime or some other common index Ed.

Floating rate loans are tied to LIBOR (at least for now, eventually LIBOR is going away) and that index is forecast to decrease from where it is today and remain relatively level for the next ten years. 

Whether you do it with real estate or index funds (or something else that works for you) is an implementation detail.

I also want at least two years of living expenses in savings accounts insured by the FDIC or NCUA.I have $2,500 a month of living expenses (frugal lifestyle), but the formula is scalable to whatever lifestyle you want to engineer for yourself.Some derive their investment income from index funds, others use income property, and others mix and match their investment income from a variety of sources.

Stocks, businesses, index funds, etc can all work.

In 2017 I had over 20% ROI on my index funds, not that I may lose all that return this year, who knows. 

The fresh air is amazing, and "biking for dollars" is fun :) I also love personal finance and geeking out on index funds and compound interest :) I'm learning first hand how much knowledge everyone I meet has to offer!

That calculation is for people who have their net worth invested in index funds.