Project Performance Reporting - Multi Currency

I am hoping someone can give me a better understanding on how the PJT Module Summarizes data in multiple currencies, which rate types are used, and how it is shown in the Project Performance Reporting Page.

Here is the example:

Project Currency = CAD (Conversion = Corporate Rate)

Project Functional = EUR (Conversion = Corporate Rate)

Global Currency = USD - BIS: Primary Currency = USD

BIS: Primary Rate Type = CT_FORECAST_RATE

Usually the Project Currency would be EUR as well here but in this example the customer is a CAD Customer and places an order (PO) in CAD Dollars in a European Country.

So the Agreement is created in CAD Dollars, Funding is done in CAD Dollars and Invoicing is done in CAD Dollars. Budgets and Forecasts entered in CAD Dollars as well. I understand when transactions are processed system will utilize corporate rate to convert to Project Currency and Project Functional Currency and I am guessing this is how the actuals amounts are summarized into CAD and EUR dollars in the Performance Reporting. But how is the summarization process converting actuals to USD (Global Currency) in the performance reporting pages and what rate is it using?