Based on the given feature description, the feature "Repetition" is not directly related to the task of predicting the grain yield of the soybean cultivar. The feature "Repetition" represents the number of times an experiment or observation is repeated for a particular cultivar, and it does not provide any information about the potential grain yield.

To create the requested dictionary, where we include 5 typical Repetition values for each target class ('low' and 'high'), we can provide a general analysis with arbitrary values for demonstration purposes. Since the feature description does not specify the possible range of values for "Repetition", we will assume it can take values between 1 and 10.

```json
{
	"low": [1.0, 2.0, 3.0, 4.0, 5.0],
	"high": [6.0, 7.0, 8.0, 9.0, 10.0]
}
```

Please note that these are arbitrary values provided for demonstration purposes. In a real analysis, the actual relationship between the feature and the target class should be determined using domain knowledge, data analysis techniques, or statistical methods.