我的理解是

这两个schedules are derived by summing up all the relevant demands and supplies respectively

因为整个市场是由许多个体组成的，所以这个两个schedules是诸多个体需求与供给的summation

我是做国贸与会计的，经济学只能蒙了

楼主有答案了，还请贴出来

"The supply and demand for foreign-exchange is considered to be derived schedules. Explain and give examples.” 根据我的理解，这题是说supply和demand是两个派生项目，所以要解释来源于哪里，并举例
回答如下：
The supply and demand for foreign exchange is derived from the credit (debit) items on the balance of
payments, such as exports or investment flows.
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