Based on my prior knowledge, I can analyze the relationship between the RIDAGEYR feature and the age group task. 

Typically, we can consider the age group of 65 and above as senior citizens and below 65 as non-senior or adult individuals. 

Using this analysis, I can create a dictionary with typical RIDAGEYR values for each target class as follows:

```json
{
	"Adult": [18.0, 30.0, 45.0, 50.0, 60.0],  
	"Senior": [65.0, 70.0, 75.0, 80.0, 90.0] 
}
```

Please note that these values are examples and can vary depending on the dataset.