The relationship between feature PAQ605 and the task of predicting the person's age group (senior or non-senior) can be analyzed by considering the association between physical activity and age. Typically, individuals who engage in moderate or vigorous-intensity sports, fitness, or recreational activities are more likely to be younger and therefore classified as non-senior. On the other hand, individuals who do not partake in such activities are more likely to be older and classified as senior.

Based on this analysis, we can create the following dictionary:

```json
{
	"Adult": [1.0, 1.0, 1.0, 1.0, 1.0], 
	"Senior": [2.0, 2.0, 2.0, 2.0, 2.0]
}
```

In this dictionary, the feature values for the target class "Adult" are all 1.0, representing that the respondents in the non-senior age group engage in weekly moderate or vigorous-intensity physical activity. The feature values for the target class "Senior" are all 2.0, indicating that respondents in the senior age group do not partake in such activities.