# X-bar 12-bar Blues

Music and Lyric © 2018 Lawrence M. Lesser

When learnin’ ‘bout the mean, we wanna set a high bar;
Like the symbol for sample mean, we need a high bar!
More than procedure, here’s what its features are!

No bigger than the max, no less than the min;
Never past the max, or less than the min.
That makes a window x-bar is always in!

A value that equals 0 is part of the dataset.
If a value equals 0, it’s still in the dataset,
And sways calculation of the x-bar you get.

The mean might not have a value in reality,
Might not be a data point or value that could be:
Don’t know no household holdin’ 2.53!

Lay all the data points on a number line,
Lay all the data points on a weightless number line:
You’ll find at x-bar, it’s balanced fine!

Redistribute values so they’re all the same,
Level off the values so they’re all the same:
This fair share value the mean attains.

Take a deviation of each value from the mean,
Take a deviation of each value from the mean:
They all sum to 0: the proof is routine.

(Repeat Verse 1, changing “here’s” to “we know”)

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