can I make a bell curve from this data?

  • Thread starter Thread starter BunnyFoof
  • Start date Start date
B

BunnyFoof

A colleague at work asked if I could put some simple Excel data into a
bell curve. I don't know what I'm doing, math-wise, and I don't know
if my data even lends itself to a bell curve. Here it is:

We have 19 cars in our division. There are usually 3 cars that are
driven a lot and 3 that don't get driven much, so we periodically
rotate the highs and lows so that mileage somewhat evens out.

So what I have is the annual mileage for each car. My colleague is
hoping this will look great on a graph. Can this be put into a bell
curve format? Or would some faux work-around make it look enough like
one?

Thanks in advance,
Linelle
 
Linelle -

Enter the 19 annual mileage values in a column.

Enter five to ten equally-spaced "bin" values in another column. (For
example, if your mileage values range from 11,000 to 23,000, enter 10000,
12000, 14000, 16000, 18000, 20000, 22000, 24000 in a column.)

Choose Tools | Data Analysis | Histogram. (If you don't have Data Analysis
on the Tools menu, try Tools | Add-Ins, and check its box. If it's not
there, run your Office/Excel setup on CD to add it.)

This'll prepare a frequency distribution and column chart (histogram).

The shape may be mound-shaped (bell curve) or not.

- Mike Middleton, www.usfca.edu/~middleton
 
Bunny,

If you are taking steps to rotate the highs and lows as you put it so the
usage evens out, and that program has been effective, your frequency
distribution of usage should be fairly tight. And if your ranges are on the
large side, you may find that the histogram is more meaningful with smaller
ranges.

Also, it may be helpful to report the average and the standard deviation.

PC
 
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