Based on prior knowledge, the body mass index (BMI) can be used as a key indicator to determine if a person has diabetes or not. A higher BMI is often associated with an increased risk of developing diabetes. 

Here is the analysis and the dictionary for the relationship between BMI and the task of determining whether a person has diabetes or not:

```json
{
	"yes": [30.0, 32.5, 35.2, 37.8, 40.1],
	"no": [18.5, 20.2, 22.7, 24.9, 26.8]
}
```

In this dictionary, the key "yes" represents the target class with diabetes, and the key "no" represents the target class without diabetes. For each target class, there are 5 typical BMI values provided as floats.

Please note that the provided BMI values are just examples and may not accurately represent the actual BMI ranges associated with the task of determining diabetes. Further analysis and domain-specific knowledge are required for a more accurate understanding of the relationship between BMI and diabetes.