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An Outlier: Early Roost in Mexico?
An Outlier: Early Roost in Mexico?'

An "outlier" is a data point that differs widely from the rest of the data. Outliers raise questions. They may indicate something is wrong with the data point and should be examined carefully. What do you make of the early roost report in the Mexican state of Guanajuato? The observer reported 100 monarchs in a town that's only 100 miles from the overwintering region. He could not provide a picture because the butterflies stayed for only a day.

1. Give reasons why the roost report from Guanajuato is an outlier.


2. What questions do you have about the sighting?