Based on prior knowledge, the feature fnlwgt represents the number of units in the target population that the responding unit represents. It is a numeric variable and can potentially have a wide range of values.

To analyze the relationship between fnlwgt and the target variable, we need to examine the distribution of fnlwgt values for each target class.

Here is the dictionary with the approximate ranges of fnlwgt values for class 'no' and class 'yes':

```json
{
    "no": [550000, 600000, 650000, 700000, 750000],
    "yes": [100000, 150000, 200000, 250000, 300000]
}
```

Please note that these are just approximate ranges based on the given feature description. The actual ranges may differ depending on the dataset and specific analysis.