Upon analyzing the relationship between the feature LBXIN (Respondent's Blood Insulin Levels) and the task of predicting the person's age group, we can make certain assumptions based on prior knowledge:

1. Insulin levels tend to increase with age due to the natural decline in insulin sensitivity.
2. Insulin resistance tends to affect older individuals more often, leading to higher insulin levels.
3. Insulin levels can also be influenced by other factors such as overall health, diet, and exercise habits.

Based on these assumptions, we can infer that the LBXIN values for the target class 'Adult' would generally be lower compared to the target class 'Senior'.

Now, let's create a dictionary with the requested format, including 5 typical LBXIN values for each target class:

```json
{
	"Adult": [5.2, 6.1, 7.0, 8.3, 9.4],
	"Senior": [9.7, 10.2, 11.8, 12.9, 13.5]
}
```

Please note that the LBXIN values provided above are just examples and may not reflect the actual ranges for the target classes. For accurate predictions, a dataset with actual values and corresponding age group labels would be required to determine the appropriate ranges.