Standard deviation, coefficient of variation

Two stocks with actual returns as follows are being considered by me as an investor. Assist me by calculating the standard deviationand the coefficient of variationand avise me based on a comparison of risk and return.

Stock X – Actual Returns: 6%, 12%, 8%, 10%

Stock Z – Actual Returns: 9.5%, 9.25%, 8%, 9%

Calculates the standard deviation and the coefficient of variation for returns on two stocks.