Vol. 6, No. 9
Professor Cleary's Quality Quiz is the most-frequently-visited feature of the PQ Systems Quality eLine each month.
Once again Marge Orrine (nee Marge N. Avera) is pursuing an undaunted quest for Black Belt, in spite of setbacks and small misunderstandings (as we saw last month, this included understanding the meaning of "average"). She wants to save Natural Dairy Products money and be the first woman Black Belt in her organization.
Now that she understands central location (mean, median, mode) and variability (standard deviation), she has a firm basis for further learning about the shape of distributions and the meanings of those shapes.
the 50 data points related to the weight of butter packages--data that
she had collected and used to further her understanding of variability--Marge
begins by creating a histogram of the weights in order to respond to
her department head’s question about skewness of the data.
Aweigh, Marge's boss, comments that the histogram reveals a skewness
of -.4. Marge interprets this observation as a sign that the data has
been entered wrong and the histogram is therefore somehow flawed. She
sets out to change the data slightly in order to correct what she perceives
as a defect, and make it come out right. Is she correct?
2004 PQ Systems.
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