Is credit card transaction exchange rate passed from Mobile Expenses to iExpenses?

Hi,

Attempting to work out the exchange rate behavior for Mobile Expenses.

Example:

Foreign currency credit card transaction is attached to an expense in Mobile Expenses and then the report is submitted.

I understand that the only exchange rate available in the app is the one from the last sync. And I understand that iExpense will recalculate amounts once the expense report is received from the mobile device to the "correct" exchange rate. (Doc ID 2031166.1)

But, what is the "correct" exchange rate? Is it using the corporate rate or the exchange rate from the credit card transaction?

Thank you.

Jeanne