They only state the average when they should also state the median along with the entire data set. Let's say they sent 10 shoes of each type. Nine shoes of each

They only state the average when they should also state the median along with the entire data set. Let's say they sent 10 shoes of each type. Nine shoes of each type took exactly the same time. But one pair of Atheist shoe was delayed by 100 days. Now, on average, atheist shoes take 10 days longer to arrive because one of the pairs took 100 days longer to arrive.