PLEASEE HEL An eye doctor charges an exam fee, plus a charge for the number of boxes of contact lenses purchased.
•Lindsey had an exam and ordered 2 boxes of contact lenses for $112.97
•Josh had an exam and ordered 6 boxes of contact lenses for $272.93
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How much is the exam fee?

Her conclusion that 90% of the student body wants the colors changed is an INCORRECT conclusion. The 90% out of 100% is not referring to the total numbers of the student body.For example, 100 people are members of student body if only 50 members responded the survey, then we have:
 90% of 50 members who answered the survey said that they want the changed.