StatisticsdrillOutliers by the 1.5 × IQR rule
A statistics problem from Statisticsdrill. Solve it with one answer box, with a fresh sample on every attempt and the worked steps and spreadsheet function in the answer, and it is checked the moment you submit.
The task
Here are 13 minutes to resolve a support ticket (minutes): 25, 33, 28, 40, 18, 23, 76, 19, 71, 32, 16, 27, 76. Using the 1.5 × IQR rule with inclusive quartiles (QUARTILE.INC), a value is an outlier when it lies below Q1 - 1.5 × IQR or above Q3 + 1.5 × IQR. How many of the values are outliers? Give a whole number.
What this problem teaches
The fences come from the quartiles, which the outliers themselves barely affect. A rule based on the mean and standard deviation is pulled toward the outliers it is trying to find.
A hint if you get stuck
Find Q1, Q3 and IQR = Q3 - Q1. The fences are Q1 - 1.5 × IQR and Q3 + 1.5 × IQR. Count the values outside them.
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