4 Alun, a baker, delivers bread to community shops located in Aber, Bangor, Conwy, and E'bach.
Alun starts and finishes his journey at the bakery, which is located in Deganwy.
The distances, in miles, between the five locations are given in the table below.
| Aber | Bangor | Conwy | Deganwy | E'bach |
| Aber | - | 9.1 | 10.0 | 12.3 | 17.1 |
| Bangor | 9.1 | - | 15.5 | 17.8 | 22.7 |
| Conwy | 10.0 | 15.5 | - | 2.4 | 7.6 |
| Deganwy | 12.3 | 17.8 | 2.4 | - | 8.0 |
| E'bach | 17.1 | 22.7 | 7.6 | 8.0 | - |
The minimum total distance that Alun can travel in order to make all four deliveries, starting and finishing at the bakery in Deganwy is \(x\) miles.
4
- Using the nearest neighbour algorithm starting from Deganwy, find an upper bound for \(x\)