Calculating Rates of Return Although appealing to more refined tastes, art as a collectible has not always performed so profitably. During $2010,$ Deutscher$-$Menzies sold Arkies under the Shower, a painting by renowned Australian painter Brett Whiteley, at auction for a price of $$1,100,000.$ Unfortunately for the previous owner, he had purchased it three years earlier at a price of $$1,680,000.$ What was his annual rate of return on this painting?