Based on prior knowledge, blood insulin levels can vary based on age and health conditions. In general, insulin levels tend to increase with age, so it is possible that higher insulin levels may be associated with the senior age group. However, it is important to note that the specific range of values for insulin levels that differentiate between adult and senior age groups may vary depending on the population and health context.

To analyze the relationship between the feature LBXIN (Respondent's Blood Insulin Levels) and the target (age group), we can examine the distribution of LBXIN values for each age group.

Considering that the task is to predict whether a person belongs to the senior or non-senior age group, we can assume the following age groups: 'Adult' and 'Senior'.

An example dictionary presenting the relationship between LBXIN and the target classes could look like this:

```json
{
	"Adult": [10.5, 15.2, 20.1, 25.3, 30.0],
	"Senior": [28.6, 32.8, 36.4, 40.2, 45.1]
}
```

In this example, the five typical LBXIN values for the 'Adult' age group are [10.5, 15.2, 20.1, 25.3, 30.0], while the five typical LBXIN values for the 'Senior' age group are [28.6, 32.8, 36.4, 40.2, 45.1].

Please note that these values are just examples and for an accurate analysis, it is essential to consider the specific population and context in which the data is collected.