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Will Six Sigma Be Relevant For The Future

Box Plot

  • A Box plot or Box and Whisker Plot Provide a graphical summary of the distribution of data points in a data set.
  • It also provides insights to Overall shape of the data, Central Tendency, and Variability.
  • A boxplot works best when the sample size is at least 20

A box Plot include:

  • BOX – represents the middle 50% values of the data set.
  • MEDIAN – represents the point for which 50% of the data points are above and 50% of the data points are below in the line.
  • Q1 – Q1 represents the point for which 25% of the data points are below and 75% of the data points are above in the line.
  • Q3 – Q3 represents 75% of the data points are below and 25% of the data points are above in the line.
  • LINES – These vertical lines represent a whisker which joins Q1 or Q3 with the farthest data point but other than the outlier; Maximum Value = Q3+1.5(Q3-Q1) ; Minimum Value = Q1-1.5(Q3-Q1)
  • ASTERIX – represents an outlier and is a point which does not belong to the family of Xs in the data

Let us look at an example of box plot.

Will Six Sigma Be Relevant For The Future
  • The boxplot represents the marks scored by the students in three different subjects (Maths, Science and English) out of 40 with pass mark of 15.
  • Will Six Sigma Be Relevant For The Future
  • The highest marks was scored in maths and lowest marks was scored in Science.
  • Overall students performed well in maths and poor in science than the other.
  • In English, students doesn’t seem to perform good as the 50% of the sample scored less than 21.
  • Investigate the causes and improve by eliminating or reducing the cause.

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