1. Shawn wants to buy a new telescope. He estimates that it will take him one year to save the money and that the telescope will cost $200. At an interest rate of 6% per year, how much does Shawn need to set aside today to purchase the telescope in one year?

2. You have credit card interest rate at a fixed APR of 38.7%. The credit card payments are monthly and interest is compounded monthly. What is the monthly interest rate?

3. An asset had annual returns of 7.2, 11.5, 10.5, and 7.5 percent, respectively, for the past four years. What is the standard deviation of these returns?