Unformatted text preview: ppose there are 6 people in a room with ages 8, 9, 10, 39, 40, and 41. Calculate the mean and the
median. Clearly, neither the mean (mean = 24.5) nor the median (median = 24.5) are representative
of any ages in the room. These ages form a bimodal shape with the first mode representing children
and the second mode representing adults. Further more, this bimodal distribution is symmetric. (Note
how the mean and median are equal.) With such a shape, neither the mean nor the median should
be used to describe the center as these summary measures could mislead people in thinking that
most people in the room are around 25 years old. A bimodal distribution is probably an indication of a
third categorical variable having an influence on an analysis. In this case, that third variable is “age”
which could be categorized into children and adults. So, instead of analyzing everyone together, it is
best to report a mean (or median) for the children (mean = median = 9 years old) and a mean (or
median) for the adults (mean = median = 40 years old)...
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This document was uploaded on 02/15/2014 for the course STAT 351 at Oregon State.
- Spring '14
- Normal Distribution