Final answer:
The most Apple could charge on iTunes for a 15-track CD should be less than or equal to the cost of buying a physical CD and the time taken to rip the tracks to an iPod, considering both actual monetary costs and opportunity costs to remain competitive.
Step-by-step explanation:
The subject of this question is Mathematics, specifically dealing with the concept of cost analysis in a real-world application. The grade level of this question is High School since it includes financial reasoning which is typically taught at this level.
To answer the question, if the cost of buying a CD and ripping the tracks to your iPod is given, then the most Apple could charge on iTunes for a 15-track CD should not exceed this cost. The reason is, consumers generally opt for the cheaper option when given two equivalents. So, for Apple to remain competitive, the price on iTunes should be less than or equal to the total cost incurred from buying and ripping a CD.
This calculation would become more personalized if the value of an individual's time is taken into account, as time spent ripping the CD has an opportunity cost that should be factored into the total expense. However, since the question provides no specific cost, a general response without numerical examples can only suggest that Apple's iTunes price for a 15-track CD should be set at a point where it is seen as the more convenient or cheaper alternative to the manual process of CD ripping.