Final Tip is not calculated right. #52
Description
It seems the calculation from the final tip is wrong.
It calculates the middle between the 2,5 KSM and the 1 KSM tip, although it should calculate the middle between 2,5 KSM and 2,5 KSM.
Polkassembly URL: https://kusama.polkassembly.io/tip/0x75794c0b64bcb2791e4fe4fd3836fcbd20ee3761d3a8e5b016a88ce4cd1ff711
On Polkadot.js it is calculated correctly.
