In: Finance
Over the past four years, a stock produced returns of 13, 6, -5,
and 18 percent, respectively.
What is the standard deviation of these returns? What would be the
standard deviation of these returns if they were exactly twice the
return shown for each year? please show your work.
Year | Yearly Return | Xi - Average Return | (Xi - Average Return)^2 |
i | A = Xi | B = A - 8% | C = B^2 |
1 | 13 | 5 | 25 |
2 | 6 | -2 | 4 |
3 | -5 | -13 | 169 |
4 | 18 | 10 | 100 |
Average | 8 | 298 |
Variance = Sum(Xi - Average Return)^2 / n |
Variance = 298 / 4 |
Variance = 74.5% |
Standard Deviation = Square Root of Variation |
Standard Deviation = 74.5^(1/2) |
Standard Deviation = 8.63% |
If they were exactly twice the return shown for each year, The standard deviation also doubles as it is a relative measure.
Year | Yearly Return | Xi - Average Return | (Xi - Average Return)^2 |
i | A = Xi | B = A - 8% | C = B^2 |
1 | 13**2 = 26 | 10 | 100 |
2 | 6%*2 = 12 | -4 | 16 |
3 | -5% * 2 = -10 | -26 | 676 |
4 | 18%*2 = 36 | 20 | 400 |
Average | 16 | 1192 |
Variance = Sum(Xi - Average Return)^2 / n |
Variance = 1192 / 4 |
Variance = 298% |
Standard Deviation = Square Root of Variation |
Standard Deviation = 298^(1/2) |
Standard Deviation = 17.26% |