A customer service center keeps track of the number of complaints received each day about one of their new products.The numbers of complaints received over the last 11 day period are 19, 18, 22, 21, 17, 18, 22, 19, 16, 23, and 25.The IQR for this sample of data is
A)25.
B)22.
C)18.
D)9.
E)4.

Question

Quizplus · Accepted Answer

The Interquartile Range (IQR) is calculated by subtracting the first quartile (Q1) from the third quartile (Q3). First, we need to order the data from smallest to largest: 16, 17, 18, 18, 19, 19, 21, 22, 22, 23, 25. With 11 data points, the median (Q2) is the 6th value, which is 19. Q1 is the median of the first half (excluding the median if the number of data points is odd), which is 18. Q3 is the median of the second half, which is 22. Therefore, IQR = Q3 - Q1 = 22 - 18 = 4.

A Customer Service Center Keeps Track of the Number of Complaints