Difference in the quotes between brokers

Hi all ,

I have MT4 platform from Northfinance AS of 6.45 EST USD/CAD did not touch 1.0775 . But one of my position was closed with a different broker at this rate . Any reasons why or how this could have happened.

Thanks,
Ananth

There is no centralized exchange in forex, and therefore no "correct" or "incorrect" price.