Please answer each question individually.

1. We measure risk by looking at the variability of a stocks return. However, why is the standard deviation of a single stock not the true measurement of its risk?
2. If a 10 year bond is callable by the issuer after 5 years, will that lead to a higher or lower yield compared to similar bonds without the call feature?
3. How much would you have to save every month to have $500,000 in 40 years time assuming you could achieve at least a 10% per year return?