7. You invest 49% of your money in Stock A and the rest in Stock B. The variance of annual returns is 38% for Stock A and 40% for Stock B. The correlation between the two stocks is -0.6. What is the standard deviation of annual returns for the combination of the two stocks? Go out three decimal places - for example, write 39.6% as .396.

8. Stock A's annual returns have a standard deviation of 37%. Stock B's annual returns have a standard deviation of 71%. The two stocks have a correlation of 0. Use calculus to find out what percentage of your money you should invest in Stock A in order to minimize the standard deviation of a portfolio of A and B. Go out four decimals - in other words, you should write 31.68% as .3168.