Eleven high school teachers were asked to give the number of students in their classes. The sample datafollows. Would any of the class sizes be considered an outlier?
$$36,31,30,31,20,19,24,34,21,28,24$$
A) No
B) Yes

Question

Eleven high school teachers were asked to give the number of students in their classes. The sample datafollows. Would any of the class sizes be considered an outlier?
$$36,31,30,31,20,19,24,34,21,28,24$$
A) No 
B) Yes

Quizplus · Accepted Answer

To determine if there is an outlier, we can use the interquartile range (IQR) method. First, we find the median, lower quartile (Q1), and upper quartile (Q3). The sorted data is: 19, 20, 21, 24, 24, 28, 30, 31, 31, 34, 36. The median is 28, Q1 is 21, and Q3 is 31. The IQR is Q3 - Q1 = 31 - 21 = 10. An outlier is a value below Q1 - 1.5*IQR or above Q3 + 1.5*IQR. Calculating these, we get 21 - 15 = 6 and 31 + 15 = 46. Since all class sizes are between 6 and 46, there are no outliers.

Eleven High School Teachers Were Asked to Give the Number 36,31,30,31,20,19,24,34,21,28,2436,31,30,31,20,19,24,34,21,28,2436,31,30,31,20,19,24,34,21,28,24

Eleven High School Teachers Were Asked to Give the Number $36,31,30,31,20,19,24,34,21,28,24$