フリー問題

問題文

A revenue column has a mean of 180 and a median of 42. Which single summary should the analyst report to a business audience, and why?

選択肢

1. The mean, after removing all values above the 99th percentile; trimming the extreme tail pulls the average back close to the center of the distribution and keeps a familiar figure in the report.
2. Neither, because a single number cannot summarize a skewed distribution, so the report should contain only the full histogram and leave the audience to read the typical level off the chart.
3. The median, because the large gap shows a long right tail, and the median describes the typical customer while the mean is pulled up by a few very large values.
4. The mean, because it uses every observation and therefore contains more information than the median, which discards the magnitude of all values except the one that happens to sit in the middle of the sorted order.