It seems like I was attempting to state the final number is the mathematical median of the adjusted group.

I did it by brute force and came up with 16.8% if the compounding is daily.But, while this is mathematically an annuity, its not what would commonly be called an annuity.

What some people do, and mathematically it makes sense, is to open a new credit account during a 0% for the first year promotional offer, transfer existing balances from a high interest card, and close the old account. 

Especially for the "small fish" owners that mathematically is not worth their attentions.

If that happens every year  mathematically I’d be better suited to just let the tenants stay at the current rate until they decide to leave and then turn over the unit and move the rent to market rate and repeat the process it’s the same amount of revenue (or more) with zero annual turnover headaches 

The listing agent did tell us she thought the seller still owed at least $168k, which appears to be mathematically feasible. 

The naturally thing that comes to mind is, how does this ROE calculation relate to ROI/IRR (both in practical and mathematical senses) and should one metric be considered more strongly over another in certain situations.

Is there any kind of mathematical formula or equation I can use when trying to see if a duplex will benefit me using the first time buyer loan ?

This is mathematical.

I have been away from this thread for a while, hence the tardy response.Jon Holdman pointed out via a precise mathematical calculation of how using leverage is beneficial to a certain extent.