The sample standard deviation equals the square root of the sum of the squares of the position returns less the mean return, divided by the number of observations in the sample minus one.
|
Position |
Return (%) |
(Return – Mean)2 |
|
A |
1.3 |
0.60 |
|
B |
1.4 |
0.46 |
|
C |
2.2 |
0.02 |
|
D |
3.4 |
1.76 |
|
Mean |
8.3/4 = 2.075 |
Sum = 2.83 |
|
Std. Dev. = [2.83 / (4 – 1)]0.5 = 0.97 |
