Determine the average annual rate of return for each of the investments below. Assume that you buy $$10,000$

in stock in all four cases, and ignore interest and transaction costs in all your calculations.

a$)$ Buy a stock for $$70$ without margin and sell it two vears later for $$50.$

b$)$ Buy a stock for $$30$ with $20\%$ margin and sell it two years later for $$45.$

c$)$ Buy a stock for $$40$ with $70\%$ margin and sell it three years later for $$25.$

d$)$ Buy a stock for $$25$ without margin and sell it a year later for $$49.$