Based on my prior knowledge, I can analyze the relationship between the feature BMXBMI and the age group (target variable) to determine the appropriate ranges of values.

To differentiate between 'Adult' and 'Senior' age groups, I will consider the following ranges:

1. Adult age group: BMXBMI values typically range from 18.5 to 24.9. This range is associated with a healthy weight and is commonly seen in younger adults.

2. Senior age group: BMXBMI values typically range from 25 to 29.9. This range is associated with overweight conditions and is commonly seen in older adults.

Based on these ranges, I will generate the dictionary as requested:

```json
{
	"Adult": [18.6, 21.3, 23.8, 19.4, 24.1],
	"Senior": [25.2, 28.6, 26.9, 29.1, 27.5]
}
```

The 'Adult' list contains typical BMXBMI values for the adult age group, while the 'Senior' list contains typical BMXBMI values for the senior age group.