1. you wish to buy a stock on margin. If you have $8400 to invest and the initial margin requirement is 50%. The maintenance margin is 40%. AAPL is selling for $140 per share now. (1) how much you can borrow if you want to buy as many AAPL shares as you possibly can? Also show me the initial balance sheet. (2) After your purchase, one year later, AAPL falls to $135 per share. Do you subject to a market call when AAPL falls to $135 per share one year later? Why? Show me how to get the new margin. (3)At what price are you subject to a margin call?