| Interval minus mean | Residual | Square of residual | |
|---|---|---|---|
| 28 - 27.38 | 0.62 | 0.3844 | |
| 27 - 27.38 | -0.38 | 0.1444 | |
| 28 - 27.38 | 0.62 | 0.3844 | |
| 27 - 27.38 | -0.38 | 0.1444 | |
| 27 - 27.38 | -0.38 | 0.1444 | |
| 27 - 27.38 | -0.38 | 0.1444 | |
| 28 - 27.38 | 0.62 | 0.3844 | |
| 27 - 27.38 | -0.38 | 0.1444 | |
| 28 - 27.38 | 0.62 | 0.3844 | |
| 27 - 27.38 | -0.38 | 0.1444 | |
| 27 - 27.38 | -0.38 | 0.1444 | 28 - 27.38 | 0.62 | 0.3844 |
| 27 - 27.38 | -0.38 | 0.1444 | |
| Sum of squares | 3.0772 | ||
N (number of intervals) = 13
N(N-1) = 13 X 12 = 156
Uncertainty = square root of (3.0772/156) = 0.1404, or to two decimals 0.14
"Error" in units of uncertainty = (27.38 - 27.32)/0.14 = 0.06/0.14 = 0.43