A researcher decides to split scores on an exam into quartiles.She determines that a score of 64 is at the 25th percentile,a score of 74 is at the 50th percentile,and a score of 80 is at the 75th percentile.What is the interquartile range (IQR)for these data?
A) 16
B) 10
C) 6
D) There is not enough information to answer this question.

Question

Quizplus · Accepted Answer

Since the scores are divided into quartiles, the 25th percentile represents the lower quartile (Q1), the 50th percentile represents the median (Q2), and the 75th percentile represents the upper quartile (Q3). Therefore, Q1 = 64, Q2 = 74, and Q3 = 80. The IQR is the difference between the upper and lower quartiles, which is Q3 - Q1 = 80 - 64 = 16. So, the answer is A) 16.

A Researcher Decides to Split Scores on an Exam into Quartiles.She