aeros232 wrote:

97 students take part in a test and the median score is 85. Which of the following descriptions must be correct?

I. At least 49 students’ score are equal to or more than 85.

II. At least 49 students’ score are less than 85.

III. At most 49 students’ score are equal to or more than 85.

A. I

B. II

C. III

D. I & II

E. I & III

Need help since I don't agree with the answ.

median is 85. it means 48 scored up to 85, INCLUSIVE. the 49th scored 85, and 48 scored at least 85 and more.

1. YES, at least 49 scored at least 85 or more. this one we know for SURE, since the 49th person in the middle scored 85, and there are 48 more people with either 85 or MORE. so I is true. we can eliminate B and C.

2. NO, even if everyone got a different score, there are 48 people who scored below 85. since the middle person, 49th one scored 49, and the rest 48 scored 85 or more, this case is never true. D eliminated.

3. at most 49 students got 85. this is a tempting one but NO. suppose all 97 students got 85. the median is still 85, but the statement is not true. E is eliminated, and only A stands.