From the given feature description, LBXGLT represents the respondent's oral glucose level. To determine the appropriate ranges of values for this numeric variable, we need more information about what constitutes a high or low glucose level. Without that information, it is difficult to determine the appropriate ranges.

Assuming we have no additional information, we can analyze the relationship between LBXGLT and the target age group by looking at typical glucose levels for different age groups. It is generally believed that glucose levels tend to increase with age, so we can expect higher glucose levels in the senior age group compared to the non-senior age group.

Based on this assumption, we can create a dictionary with the possible LBXGLT values for each target class:

```json
{
    "Adult": [70.2, 85.4, 90.1, 95.8, 100.2],
    "Senior": [90.5, 100.6, 105.3, 110.2, 120.4]
}
```

Please note that these values are just examples and do not represent actual glucose levels. The appropriate ranges of values for LBXGLT would depend on the specific dataset and the domain knowledge of glucose levels.