HP 12C

Hello everyone, Last miles!! I wonder if someone could share tips or shortcut to calculate the standard deviation on HP 12C when we are given 4 returns of a portfolio? It tooks ages if calcuate manually. Example is Q 1669 The historical return for each of a portfolio’s four positions is shown below. Using the population standard deviation, what is the coefficient of variation (CV) for these returns? Position Return A 17.0% B 12.2% C 3.9% D –8.4% A) 1.89. B) 1.97. C) 1.56. D) 3.12. Many thanks!

sorry, there is no shortcut.