I know Jakob is only like 17-18, and it's impossible to predict for sure how the future will go for him, but how will the rest of his career play out? What will his times be? Will he win World Championship/Olympic medals and if so how many? Honestly, I could see him reaching his PR's in the next 3 years or so considering that he's been training at a high level since he was 10, while his brothers didn't start focusing on running specifically until they were like 14 or 15. Filip and Henrik are both 25 and 27, way older than Jakob, but he's probably at or near their level of development as a runner.
My Predictions:
800m: 1:43
1500m: 3:27 at age 21-22
Mile: 3:45
5000m: 12:48
Wins Gold Medal in the 1500m at the World Championships and 2020 Olympics, then Double Olympic Champ in 2024 in 1500 and 5000m, along with 2-3 world championship medals in between.