Question

What is the standard deviation of 26%, 15%, -14%,-15%, 2%, -18%, 42%, 30%, -32% and 28%

Answer 1

Average Return = [0.26 + 0.15 + (-0.14) + (-0.15) + 0.02 + (-0.18) + 0.42 + 0.30 + (-0.32) + 0.28] / 10
Average Return = 0.64 / 10
Average Return = 0.0640 or 6.40%

Variance = [(0.26 - 0.064)^2 + (0.15 - 0.064)^2 + (-0.14 - 0.064)^2 + (-0.15 - 0.064)^2 + (0.02 - 0.064)^2 + (-0.18 - 0.064)^2 + (0.42 - 0.064)^2 + (0.30 - 0.064)^2 + (-0.32 - 0.064)^2 + (0.28 - 0.064)^2] / 9
Variance = 0.57124 / 9
Variance = 0.063471

Standard Deviation = (0.063471)^(1/2)
Standard Deviation = 0.2519 or 25.19%