An engineering team is testing the emergency braking system of a prototype autonomous warehouse vehicle. Table 1 shows the recorded braking distances, ddd, in metres, over five consecutive test runs under identical speed and load conditions on a flat concrete surface.
| Test Run | Braking distance ddd (m) |
|---|---|
| 1 | 2.15 |
| 2 | 2.11 |
| 3 | 3.98 |
| 4 | 2.18 |
| 5 | 2.09 |
Identify the anomalous value of the braking distance shown in Table 1.