Oups got it wrong . for decimals and , for thousands - the american way.
Well, as you wrote 1comma5 it is pretty clear, don't you think? Ask again for 1,500 km whether he will say onethousandfivehundred or onecommafive. Overall it is pretty clear that the OP used . as a thousand separator and not for decimals - the european way.
This is plain wrong. On standard video slot machines every single game has a random result, there is no 'memory' of past games in order to reach a certain payout percentage. There are jurisdictions and game types who do/did this (eg UK AWP, Germany street market) but in typical (Las Vegas style) casinos the hold is defind by the math of the game and is only true for large numbers of games played. A casino game can be way over or under the theoretical payout percentage even after many games played, because it is - (pseudo) random. This is tested and certified by global gaming labs like GLI and others.