Based on prior knowledge, the capacity of a car in terms of the number of persons it can carry could be a relevant factor in determining the decision to buy a car. Here is the analysis of the relationship between the feature "persons" and the target task of rating the decision to buy the car.

- Unacceptable: It is likely that if a car can only carry 2 persons, it may be considered unacceptable as it might not meet the needs of a typical family or group.
- Acceptable: Cars with a capacity to carry 4 persons may be deemed acceptable as it can accommodate a small family or a group of friends.
- Good: Cars with a capacity to carry more than 4 persons might be considered good as it can accommodate larger families or groups, making it more convenient for them.
- Very Good: It is likely that cars with a higher capacity to carry more than 4 persons would be rated as very good, as it can accommodate even larger families or groups, providing an extra level of convenience.

Using this analysis, we can create the dictionary:

```json
{
	"unacceptable": ["2"],
	"acceptable": ["4"],
	"very good": ["more"],
	"good": ["more"]
}
```

Please note that the values "2" and "4" are the possible values of the feature "persons" for the target classes "unacceptable" and "acceptable", respectively. The values "more" are the possible values for the target classes "very good" and "good", as it is not specified how many people a car can accommodate when the capacity is labeled as "more".