Below is an context that describes a sql query, paired with an question that provides further information. Write an answer that appropriately completes the request.  # noqa: E501
### Context:
CREATE TABLE Invoices (Order_Quantity INTEGER, payment_method_code VARCHAR)
### Question:
What is the average quantities ordered with payment method code "MasterCard" on invoices?
### Answer:
SELECT AVG(Order_Quantity) FROM Invoices WHERE payment_method_code = "MasterCard"