I tried to do them in different ways even thru the excel scenario tool and got it wrong. I don't know what happened. please explain thru excel or as you prefer. thank you a lot

Suppose that X Tel currently is selling at $30 per share. You buy 600 shares using $13,500 of your own money, borrowing the remainder of the purchase price from your broker. The rate on the margin loan is 6%. Required: a. What is the percentage increase in the net worth of your brokerage account if the price of X Tel immediately changes to (i) $33; (ii $30; (ii) $27 ? (Leave no cells blank - be certain to enter " 0 " wherever required. Negative values should be indicated by a minus sign. Round your answers to 2 decimal places.) b. If the maintenance margin is 25%, how low can XTel's price fall before you get a margin call? (Round your answer to 2 decimal places.) c. How would your answer to requirement b would change if you had financed the initial purchase with only $9,000 of your own money? (Round your answer to 2 decimal places.) d. What is the rate of return on your margined position (assuming again that you invest $13,500 of your own money) if X Tel is selling after one year at (i) $33; (ii) $30; (iii) $27 ? (Negative values should be indicated by a minus sign. Round your answers to 2 decimal places.) e. Continue to assume that a year has passed. How low can XTel's price fall before you get a margin call? Note: Assume maintenance margin of 25% (Round your answer to 2 decimal places.)