Final answer:
The question appears to relate to a mathematics probability problem but doesn't provide enough context to determine the sizes for Grilled Catfish. Further information is necessary for a precise answer.
Step-by-step explanation:
The question indicates a scenario involving probability, which is a concept studied in mathematics, particularly as part of a high school curriculum. The question does not provide specific sizes for the grilled catfish but rather implies a probability calculation problem regarding different meat portion sizes. To accurately answer the question pertaining to the sizes available for Grilled Catfish, additional context or information from a menu or dataset is required. As such, presently we are unable to determine the sizes for Grilled Catfish without further details.