(Related to Checkpoint 7.1) (Calculating rates of return) On December 17, 2007, the common stock of Google Inc. (GOOG) was trading for $669.23. One year later the shares sold for only $315.24. Google has never paid a common stock dividend. What rate of return would you have earned on your investment had you purchased the shares on December 17, 2007? The rate of return you would have earned is %. (Round to two decimal places.)