Based on your description, the feature is the plant height (IFP) in centimeters and the task is to determine whether the grain yield of the soybean cultivar will be low or high. To analyze the relationship between the feature and task, we need to consider the prior knowledge about soybean cultivars.

Soybean plants generally have an optimal height range for maximizing grain yield. Too low plant heights may indicate poor growth and development, which could result in a lower grain yield. Conversely, excessively tall plants may allocate more resources to stem elongation rather than grain production, leading to a lower yield as well. Therefore, we can expect to see a peak in grain yield at intermediate plant heights.

To create the dictionary, let's assume the following ranges of IFP values:
- Low IFP: up to 30 cm (indicating poor growth)
- High IFP: above 60 cm (indicating excessive height)
- Moderate IFP: between 30 cm and 60 cm (indicating optimal plant height)

Based on this analysis, we can provide a dictionary with 5 typical IFP values for each target class:

```json
{
	"low": [25.0, 27.5, 28.3, 29.1, 30.0],
	"high": [62.2, 64.8, 67.3, 69.9, 71.5]
}
```

Please note that the given IFP values are just examples and might not reflect the actual ranges for soybean cultivars. The accuracy of the analysis and the ranges of IFP values provided would depend on the specific characteristics of the soybean cultivar in question and other factors that might affect grain yield.