Based on prior knowledge, we can assume that the age group "Senior" refers to individuals who are typically older than 65 years. To analyze the relationship between the feature BMXBMI and the task of predicting the age group, we need to consider typical BMI ranges for different age groups.

According to the World Health Organization (WHO), the following BMI ranges are widely used for adults:

- Underweight: BMI < 18.5
- Normal weight: 18.5 <= BMI < 25
- Overweight: 25 <= BMI < 30
- Obesity: BMI >= 30

Given that we are trying to predict whether someone is a senior or a non-senior, we can assume that seniors may have a higher likelihood of falling into the overweight or obese categories. Therefore, we can expect higher average BMXBMI values for the senior age group compared to the non-senior group.

To generate the requested dictionary, we will provide 5 typical BMXBMI values for both the 'Adult' and 'Senior' age groups:

```json
{
	"Adult": [22.5, 23.7, 24.9, 26.1, 27.3],
	"Senior": [26.8, 27.9, 29.1, 30.5, 31.8]
}
```