Nate Silver and Allison McCann's "How to Tell Someone’s Age When All You Know Is Her Name"

Nate Silver and Allison McCann (reporting for Five Thirty Eight, created graphs displaying baby name popularity over time. The data and graphs can be used to illustrate bimodality, variability, medians, interquartile range, and percentiles.

For example, the pattern of popularity for the name Violet illustrates bimodality and illustrates why measures of central tendency are incomplete descriptors of data sets:

"Other names have unusual distributions. What if you know a woman — or a girl — named Violet? The median living Violet is 47 years old. However, you’d be mistaken in assuming that a given Violet is middle-aged. Instead, a quarter of Violets are older than 78, while another quarter are younger than 4. Only about 4 percent of Violets are within five years of 47."

Relatedly, bimodality (resulting from the current trend of giving classic, old-lady names to baby girls) can result in massive variability for some names...

...versus trendy baby names that have smaller interquartile ranges...

Your blogger exceeds the 75th percentile for Jessica Age. She considers herself a trendsetter, not old for her name.