Final answer:
Without specific manufacturer's specifications for the aerial device or engine, it is not possible to accurately determine the RPM range to which the fast idle switch will increase the engine speed.
Step-by-step explanation:
The fast idle switch is designed to send a signal to the engine to temporarily increase the engine speed to assist in faster and more powerful movement for tasks such as operating an aerial device. The correct RPM (Revolutions Per Minute) range for this increased idle speed has not been explicitly provided in the question or reference information. Each vehicle or engine may have a different range for the fast idle setting. To get the precise answer, it would be necessary to refer to the manufacturer's specifications for the specific aerial device or engine in question. If the context is specific to a question on an exam or in a book, the necessary information should be available within that context to make an accurate choice. Without this specific information, it is not possible to confidently provide an accurate answer to which RPM range the fast idle switch will increase the engine to.