Analysis:

Based on my prior knowledge, blood glucose levels can vary significantly depending on age and overall health. In the context of determining whether someone falls into the senior or non-senior age group, it is important to consider the typical ranges of blood glucose levels for different age groups.

In general, fasting blood glucose levels tend to be higher in older individuals, especially those with age-related conditions like diabetes. Therefore, it is expected that the blood glucose levels will be higher for seniors compared to non-seniors.

To create the dictionary, I will identify typical fasting blood glucose level values for both the 'Adult' and 'Senior' categories.

Dictionary:

```json
{
	"Adult": [85.2, 91.5, 89.7, 87.4, 93.1],
	"Senior": [98.6, 103.2, 96.8, 100.5, 105.1]
}
```

Note: The values in the dictionary are not specific ranges but rather examples of the blood glucose levels that are commonly observed in each age group.