To analyze the relationship between the feature LBXGLU and the target task of predicting a person's age group (Senior or non-senior), we can make use of prior knowledge about blood glucose levels and age.

Typically, fasting blood glucose levels are used to diagnose and monitor diabetes. According to the American Diabetes Association, normal fasting blood glucose levels for adults without diabetes range from 70-99 mg/dL. However, as people age, the normal range for fasting blood glucose levels may increase slightly, due to age-related changes in glucose metabolism. 

Based on this information, we can assume that higher fasting blood glucose levels may be more indicative of senior age, while lower levels may be more indicative of non-senior age.

Now, let's create the dictionary with the possible values of LBXGLU for each target class.

```json
{
	"Adult": [80.0, 90.0, 85.0, 95.0, 92.0],
	"Senior": [100.0, 105.0, 110.0, 115.0, 120.0]
}
```

In this dictionary, we have provided 5 typical fasting blood glucose values for each target class. The values for the "Adult" class range from 80.0 to 95.0, while the values for the "Senior" class range from 100.0 to 120.0. These values are just examples and can vary depending on the specific dataset and population being analyzed.