Based on prior knowledge, we can assume that a person is considered a senior if their age is 65 or above. Therefore, we will define the age range of seniors as 65 and above, and the age range of non-seniors as below 65.

To conduct the analysis, we can examine the distribution of RIDAGEYR values for each target class and identify typical age values for both adult and senior classes.

Here is the dictionary with the typical RIDAGEYR values for each target class:

```json
{
	"Adult": [20.0, 30.0, 40.0, 50.0, 60.0],
	"Senior": [65.0, 70.0, 75.0, 80.0, 85.0]
}
```

These values are just examples and can vary depending on the dataset and the distribution of ages within the target classes. It is important to note that this analysis is based on prior knowledge and assumptions, and further analysis on the actual dataset is required to get more accurate and representative results.