Final answer:
If you are in the 3rd quartile of 1000 students, 250 students rank above you, as the 3rd quartile indicates you are above the bottom 75% of students.
Step-by-step explanation:
If you rank in the 3rd quartile of 1000 students, you are above the bottom 75% of students but below the top 25%. Quartiles divide the data into four equal parts. The 1st quartile (Q1) represents the top 25%, the 2nd quartile (Q2) the top 50%, the 3rd quartile (Q3) the top 75%, and the 4th quartile (Q4) the top 100%. Since you are in the 3rd quartile, 75% of the students rank below you. This means 25%, or 250 students, rank above you in this case out of 1000 students.The correct answer is a) 250.