Based on prior knowledge, the relationship between a person's body mass index (BMXBMI) and their age group can be analyzed as follows:

1. Body Mass Index (BMI) is a numerical measure of a person's weight relative to their height. It is commonly used as an indicator of body fatness and is calculated by dividing weight in kilograms by the square of height in meters.

2. In general, older adults tend to have a higher average BMI compared to younger adults. Therefore, it is likely that seniors will have a higher average BMI compared to non-seniors.

3. Identifying specific ranges of BMXBMI values for adults and seniors requires further analysis of the data and domain knowledge about the age groups being considered.

Based on these observations, we can generate a dictionary providing five typical BMXBMI values for each target class:

```json
{
	"Adult": [23.5, 26.9, 29.1, 20.3, 22.8],
	"Senior": [29.4, 31.2, 27.7, 33.8, 25.6]
}
```

Please note that these values are arbitrary and should be replaced with actual data analysis. To accurately determine the appropriate ranges of BMXBMI values for each target class, it is recommended to analyze data specific to the age groups being considered.