An outbreak of norovirus occurred after a church picnic which was attended by 515 persons. Assume everyone ate the same food items. Seventy-five people had fever and diarrhea, 5 of these people were severely affected. Subsequent laboratory tests on all who attended the picnic revealed an additional 65 cases. The attack rate of norovirus was:

Group of answer choices

14.6%

12.6%

27.2%

15.4%