Two mutual fund managers, Martha and David, have been bragging about whose fund is the top performer? Martha states that investors bought shares in her mutual fund ten years ago for $21.00 and those shares are now worth $65.00. David states that investors bought shares in his mutual fund for only $3.00 six years ago, and now they are worth $7.30. Which mutual fund manager has had the highest growth rate for the management period? Should this comparison be made over different management periods? Why or why not?