Fares and ages
extensional passenger(id: integer, survived: integer, class: integer, sex: string, fare: float).fare_by_class(Class, avg(Fare)) :-
passenger(_, _, Class, _, Fare).| class | avg fare |
|---|---|
| 1 | 84.15 |
| 2 | 20.66 |
| 3 | 13.68 |
age_by_survival(Survived, avg(Years), count(_)) :-
passenger(Id, Survived, _, _, _), age(Id, Years).| survived | avg age | count |
|---|---|---|
| 0 | 30.6 | 424 |
| 1 | 28.3 | 290 |
424 + 290 = 714 < 891: not all ages are known.