Analysis:

Based on prior knowledge, blood glucose levels can help in determining a person's age group. Generally, higher blood glucose levels are associated with older age groups, such as seniors. On the other hand, lower blood glucose levels are more common in younger age groups, such as adults.

To analyze the relationship between the feature, LBXGLU (respondent's blood glucose after fasting), and the task of predicting the person's age group (senior or non-senior), we can compare the typical ranges of LBXGLU values for each target class.

Dictionary:

Based on the analysis, the following dictionary can be created:

```json
{
    "Adult": [80.5, 85.2, 87.6, 90.1, 95.0],
    "Senior": [105.3, 110.2, 112.8, 115.7, 120.5]
}
```

This dictionary includes 5 typical LBXGLU values for each target class: "Adult" and "Senior". The LBXGLU values are presented as floats in lists. Please note that these values are just examples and may not be accurate for the specific dataset.