Assume an initial margin requirement of $50$ percent

and a maintenance margin of $30$ percent. An investor

buys $100$ shares of stock on margin at $$60$ per share.

The price of the stock subsequently drops to $$50.$

a$.$ What is the actual margin at $$50?$

b$.$ The price now rises to $$55.$ Is the account

restricted?

c$.$ If the price declines to $$49,$ is there a margin call?

d$.$ Assume that the price declines to $$45.$ What is

the amount of the margin call? At $$35?$ please answer these questions especially c and d $.$