**Myth 13: A statistician would place his head in an oven and his feet in ice, and say that on average he feels fine.**

**Truth 13**

This comical device works well to parody statisticians but is not correct in its use of statistical concepts. Clearly, no statistician would average data from two extremes because the result would not characterize either one of them. These data are produced from two different populations, and it would be like averaging apples and oranges. The statistician would have resorted to the concept of variation to describe that there is high contrast between head and feet. Another similar joke is this: John has 0 dollars and Joseph has 600 dollars, so they have 300 dollars on average. This result does not represent the reality of either one.

When the statistician averages measurements, he/she bases it on numbers that refer to the same population, delimited in space and time, and in this case the average is useful for making decisions, especially if a measure of the precision of such average is also provided. For example, the yearly average temperature in Hermosillo, Mexico is 32°C. However, if one is interested in traveling to Hermosillo in June and July, it is more useful to know that during those months the maximum daily temperature is 40°C.

When the statistician averages measurements, he/she bases it on numbers that refer to the same population, delimited in space and time, and in this case the average is useful for making decisions, especially if a measure of the precision of such average is also provided. For example, the yearly average temperature in Hermosillo, Mexico is 32°C. However, if one is interested in traveling to Hermosillo in June and July, it is more useful to know that during those months the maximum daily temperature is 40°C.

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