Analysis of the relationship between feature AST_BLOOD and the task of determining chronic heart failure:

Prior knowledge:
Serum AST (Aspartate Aminotransferase) levels can be an indicator of heart damage. In the context of chronic heart failure, elevated AST levels may be observed. However, without specific ranges or thresholds, it is difficult to determine the appropriate AST_BLOOD values indicative of chronic heart failure.

To create the required dictionary, I will assume higher AST_BLOOD values may be more indicative of chronic heart failure.

Based on this assumption, and using prior knowledge as a guide, here is a dictionary with possible typical AST_BLOOD values for each target class:

```json
{
	"no": [20.3, 21.1, 19.5, 18.7, 22.0],
	"yes": [33.4, 35.9, 31.8, 29.7, 34.2]
}
```

Please note that the specific ranges and values mentioned here are purely examples and may not reflect actual medical guidelines or thresholds. For accurate and reliable assessments of chronic heart failure based on AST_BLOOD levels, consulting medical databases, literature, or healthcare professionals is recommended.