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Statistics Normal Distribution

Statistics normal distribution is a description of how data is shaped when plotted on a frequency diagram or a histogram . Normal distribution is the most common shape of data. Below is a histogram of a data set that has normal distribution.

Introduction to Data Analysis

Training Video (Created by Quality Assurance Solutions)



Price $49.95

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Data Analysis is key to making business decisions about your process or product. To improve the process or product you have to measure it. Once you have the measurements, you need to quickly interpret the data.

This hour long video will show you how to present the data to management and others. Normally, management is not interested in the raw data. Business decisions are based on the summarized data or graphs of the data.

This course provides the basic tools for understanding, summarizing, creating graphs, and making future yield predictions with your collected data.

You will learn about

  • the types of data
  • basic statistics such as averages and variation
  • creating and interpreting histograms
  • statistics normal distribution
  • process capability
  • predicting yields
  • the relationship between process improvement and data
  • pareto charts
  • data analysis in excel

In addition you will learn how to use Microsoft Excel to conduct the data analysis. A final spreadsheet is provided for your review.

Your Satisfaction is Guaranteed.

Within 30 days, if you are not satisfied with this training video, I will refund your money.

Price $49.95

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Normal Distribution Described

With normal distribution, most of the data is in the center. As you get further away from the average, the less frequent the data appears. I drew a curve on the graph. This curve is called a bell shape curve because it looks like a musical bell. Normal distribution possesses the bell shape curve. Normal distribution will also be called bell shaped data.

The average of the data will be in the center. In some cases you will have perfect normal distribution. In this case the median = mode = mean .

You can use Microsoft Excel to create Histograms.

My First Normal Distribution

The first time I encountered normal distribution was during high school. I remember the teacher telling me that the grades would be based on the curve. I asked myself, what is this curve she speaks of? That curve was the bell shape curve or normal distribution. From my grades perspective, I just didn’t want to be on the beginning side of the curve.

Little did I know at that time, the importance of that curve. That curve represents natural variation. The bell shape curve appears everywhere. In about 90% of all data you collect meets normal distribution. Normal distribution is responsible for about 95% of all applied statistics.





Normal Distrubution and Statistics

When you have a Statistics Normal Distribution, you can apply statistics and make predictions about the data set. These statistics allows you to describe your data set in terms of averages and standard deviation.

In addition you can apply process control tools such as SPC when you have normal distribution.

Below is a normal distribution curve that is separated by 1, 2, and 3 standard deviations from the center.

99% of the data occur within +/- 3 standard deviations. You can use the below chart to see the percentage of data with each standard deviation.

If you have specifications you can conduct a process capability study on data sets with normal distribution. Quality Assurance relies on collecting data. That data needs to be studied and understood. Statistical normal distribution lets you do both.





Understanding Statistics Normal Distribution is a basic process improvement tool.



Quality Assurance Solutions
Robert Broughton
(805) 419-3344
USA
email


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