Here is how to determine the proportion of your portfolio to invest in stocks and bonds

Subtract 15 years from your age to determine the bond proportion as a starting point.  The rest should be in stocks.  So, if you are 50 years young subtract 15 years to get 35.  35% of your portfolio should be in bonds with 65% in stocks.  Adjust in increments of 5 points based on your risk appetite, but don't exceed the stock proportions below.

Aggressive:  80% stocks / 20% bonds
Moderate:  65% stocks / 35% bonds
Conservative:  50% stocks / 50% bonds