At the time of purchase, CurlyGirl Salons cost $135 per share. The current stock price is $160.53 per share. Over the five-year holding period, CurlyGirl produced the following annual returns: +0%,2%,+8%,+5%,+7%. What is the standard deviation of the annual returns for this sample? (recurring content question) 4.51% 3.93% 3.60% 3.36% 4.39%