Stock A's Returns Over the Past Ten Years Have Been

Essay

Stock A's returns over the past ten years have been: 10.0%, 8.0%, 12.0%, (5.0%), 10.0%, 12.0%, 10.0%, (4.0%), 8.0%, 9.0%.
a. What is the mean of Stock A's return over the past 10 years?
b. What is the standard deviation of Stock A's return over the past 10 years?
c. What is the coefficient of variation of Stock A's return over the past 10 years