Wireless iBeacon Receiver distace

(0.89976) * pow(ratio, 7.7095) + 0.111

this is very bad

Sorry. I don’t understand your question. Could you please describe it?

I’m working with the receiver I mentioned in the title and ptthon in a desktop app, I need to know if they have implemented something for the calculation of distance between the sender and receiver I am using this:
(0.89976) * pow (ratio, 7.7095) + 0.111

But it gives me very variable values

Here’s a function to calculate the distance of beacon. But it’s also not accuracy. It’s hard to get the exact distance by RSSI.