$1.)$ If you deposit $$5,000$ into a bank account that pays $5\%$ interest annually, how much will be in your account after $4$ years?

$2.)$ What is the present value of a security that will pay $$50,000$ in $10$ years, if securities of equivalent risk pay $6\%$ annually?

$3.)$ You currently have saved $$12,647$ in a brokerage account and you plan to deposit $$2,500$ at the end of every year until your account totals $$50,000.$ You expect to earn $8\%$ annually on the account. How many years will it take you to reach your goal?

$4.)$ You have just made your first $$5,500$ contribution to your retirement account. Assuming you earn a return of $10\%$ per year and make no additional contributions, what will your account be worth when you retire in $45$ years? What if you wait $10$ years before contributing?