You purchased 100 shares of IBM common stock on margin al $70 per share. Assume the initial margin is 50% and the maintenance margin is 30%. Below what stock price level would you get a margin call? Assume the stock pays no dividend; ignore interest on margin. Suppose that, unfortunately, the stock price drops to $48. You decide to put some additional cash to restore the margin. How much cash you need to inject to restore the maintenance margin back to 30%