Analysis of investment portfolio returns over a 20-year period showed the statistics below. (a) Calculate and compare the coefficients of variation. (b) Why would we use a coefficient of variation? Why not just compare the standard deviations? (c) What do the data tell you about risk and return?

Investment Type	Mean Return	Standard Deviation	Coefficient of Variation
Venture funds	18	12	?
Common stocks	14	16	?
Real estate	10	15	?
Federal short-term paper	6	2	?