Currency and Exchange Rate

Hi Everyone,
I’m a new user of Manager. I have a problem with the currency. I used the base currency with MMK and Bank Account with USD. All the transactions are correct. In summary, the system set $1=MMK1000.I want to change these exchange rate as $1=MMK1500.Please let me know the best solution. Thank you

under Settings you can set the exchange rates.

Before your transaction
Setting __ Exchanged Rate
Type Exchange rate