can you answer this question for me please ?

Suppose that Xtel currently is selling at $74 per share. You buy 300 shares using $15,000 of your own money, borrowing the remainder of the purchase price from your broker. The rate on the margin loan is 7%. a. What is the percentage increase in the net worth of your brokerage account if the price of Xtel immediately changes to: (i) \$83.62; (ii) $74; (iii) $64.38 ? What is the relationship between your percentage return and the percentage change in the price of Xtel? (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 (b) change if you had financed the initial purchase with only $11,100 of your own money? (Round your answer to 2 decimal places.)