Final answer:
Asking only the students in the cooking club would not produce a representative sample.
Step-by-step explanation:
The method that would not produce a representative sample to determine the favorite food of the students at the local high school is 4) Asking only the students in the cooking club. This sample would only represent the preferences of the students in the cooking club and not the entire student population. The other methods, such as asking students in the cafeteria, conducting a survey of all students, or selecting a random sample from each grade level, would provide a more representative sample.