An investor purchased 100 shares ofOmega common stock for 10,000. He held the stock for nine years.For the first four years he received annual end-of-year dividendsof $1,000. For the next four years he received annual dividends of$400. He received no dividend for the ninth year. At the end of theninth year he sold his stock for $11,000. What interest rate did hereceive on his investment?