Answer:
Turkey is more popular.
Explanation:
If in the survey about which is the favorite food on Thanksgiving, 9% answered turkey and 7/100 answered marshed potatoes, the most popular food among both is turkey.
This is so because in the case of marshed potatoes, the fact that 7 out of 100 choose this food implies that 7% of those surveyed designate it as their favorite, which is less than the 9% who choose turkey as such.