## 7QC Tools — Histogram of Discrete Data

Amrendra RoyHistogram is a pictorial view of the data set, it is like a portrait of your data. It tells you how your data looks like, where your most of the data is clustered (whether it is the mean or median is the true measure of the central tendency). In short it tells you about the distribution of the data set.

Histogram divides the data set into small sub-units, called as “classes”. This is followed by arranging data according to the class it belongs. In this way we have “class-range” along with their frequencies (i.e. how many data points are there in that class). This is followed by plotting a bar-graph of class Vs frequency, which is known as histogram.

For example

*In the check list example we have collected the data about the Reason for failure (= class) and number of defects because of that reason (= frequency).*

Now, if we plot the bar graph of the above data, we will get a histogram as shown below, it appears that defects due to reason C, D and G is more prominent and these three requires immediate attention.

*Note: *

*The above data set is a discrete variable hence, the bars of the histogram are not touching each other.*

Related Blogs

*7QC Tools: Flow Chart, Know Your Process Thoroughly*

__7QC Tools: Fish Bone or Ishikawa Diagram__

__7QC Tools: How to Extract More Information from the Scatter Plot?__

__7QC Tools: How to Draw a Scatter Plot?__

__7QC Tools: Scatter Plot — Caution! Misuse of Statistics!__

__7QC Tools — How to Prioritize Your Work Using Pareto Chart?__

__7QC Tools — How to Interpret a Histogram?__

__7QC Tools — How to Draw a Histogram?__

__7QC Tools — Histogram of Continuous Data__

__Excellent Templates for 7QC tools from ASQ__

__What are Seven QC Tools & How to Remember them?__

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