Using BGY method and data from https://finance.yahoo.com/quote/AAPL?p=AAPL, estimate whether Apple Inc. is at its optimal interest over book value (IOB). If not, how much shareholder value can Apple Inc. create by changing their leverage to optimal interest over book value (IOB)? Assume that 10% is the appropriate discount rate. How much value can Apple Inc. create by changing its cash balance? If you make assumptions, clearly state them. Show your work.