$(2$a$)$ Suppose that you purchase $300$ shares of XYZ shock at $$40$ per share by borrowing $$4,000$ from your broker. The interest rate on the loan is $10\%.$ What is the initial amount of equity?

$(2$b$)$ If the share price falls to $$30$ by the end of the year, what is the equity in your account?

$(2$c$)$ If the share price falls to $$30$ by the end of the year, will you receive a margin call if the maintenance margin is $40\%?$

$(2$d$)$ What is the rate of return on your investment at the end of the year?