D$$e Trader opens a brokerage account and purchases $300$ shares of Internet Dreams at $$40$ per share.

She borrows $$4,000$ from her broker to help pay for the purchase. The inferest rate on the loan is $8\%,$

a$.$ What is the margin in D$$e$\text{'}$s account when she first purchases the stock?

b$.$ If the share price falls to $$30$ per share by the end of the year, what is the remaining margin

in her account?

c$.$ If the maintenance margin requirement is $30\%,$ will she receive a margin call?

d$.$ What is the rate of return on her investment?

Old Economy Traders opened an account to short$-$sell $1,000$ shares of Internet Dreams from the