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About this lesson

Minitab is the most commonly used statistical application within the Lean Six Sigma community. This lesson provides a brief orientation concerning how to navigate through Minitab and shows how to use Minitab to calculate descriptive statistics for a data set. Minitab will be used in future lessons.

Quick reference

Basic Statistics in Minitab

Minitab is the most commonly used statistical application within the Lean Six Sigma community. This lesson provides a brief orientation concerning how to navigate through Minitab and shows how to use Minitab to calculate descriptive statistics for a data set.

When to use

While it is possible to do statistical analysis by hand, virtually everyone uses a software application to actually do the math.  Minitab is commonly used for SPC data analysis and chart generation.  It is easy to use, being very compatible with Microsoft Excel.

Instructions

With respect to statistical analysis for Lean Six Sigma projects, Minitab is able to do everything Excel can do and it can do much more.  Using Minitab is similar in many respects to using Excel.  The menu structure operates in a similar fashion.  The data can be copied and pasted between the two applications.  One caution, Minitab always organizes data by columns with row headings.  The Minitab screen has a spreadsheet window that operates similar to Excel.  It also has a Session Window that provides tabular results of analyses.  And for some analyses, it will provide graphs in a separate window.

Determining descriptive statistics for a data set is quite simple.

  1. Ensure your data is loaded into the spreadsheet portion of Minitab.
  2. Select the “Stat” menu.
  3. Select “Basic Statistics” from that menu.
  4. Select “Descriptive Statistics” from that menu.

At this point the descriptive statistics entry panel appears.  Before continuing, let me explain how to select data for Minitab to analyse.  This applies to any entry panel or form within Minitab.  Place your cursor in the entry window from which you are selecting data.  This will ensure that all available data columns show in the left most window of the form.  Then highlight the column you want and click on the “Select” button.  Minitab will move that column from the list of available columns into the entry window you are filing. You cannot directly type in the column, it must be selected in the manner described above.  Let’s continue with descriptive statistics in Minitab.

  1. Choose the variable by analysis by highlighting the column name with your data and clicking on Select.  The column name will move to the Variable window.
  2. Click on the Statistics button and choose from the menu the items you would like in your list of descriptive statistics.  I suggest mean, median, standard deviation skewness, and kurtosis.
  3. Click on the graphs button and select the type of graph you would like.  I suggest “Histogram of data, with Normal Curve”.
  4. Select OK and the data and graphs will display.

Hints & tips

  • Feel free to vary the statistics to include those you find meaningful for your analysis. For instance if creating box plots , be sure to include the First Quartile and Third Quartile.
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  • 00:04 Hi, I'm Ray Sheen.
  • 00:06 I've mentioned statistical analysis software applications several times.
  • 00:10 I wanna introduce you to Minitab.
  • 00:12 I'll do this by using this descriptive statistics
  • 00:15 that we were looking at with Excel.
  • 00:18 So let's talk about Minitab.
  • 00:20 Minitab is normally running a 30-day free trial.
  • 00:24 So, if you think that you might be interested,
  • 00:25 you can download it and play a bit.
  • 00:28 Also, many companies have a licensed agreement with Minitab.
  • 00:31 So, if you don't have it on your computer,
  • 00:33 you might still be able to get it through your company.
  • 00:36 Minitab is the most popular statistical software application among Lean Six Sigma
  • 00:41 practitioners.
  • 00:42 There are other very good applications available.
  • 00:45 But Minitab currently dominates the market.
  • 00:48 It is a statistical application so it can do just about anything statistically
  • 00:52 that you will want to do with your data set.
  • 00:54 And since it focuses on statistics, it's optimized around this functionality.
  • 00:59 Many tab gives both tabular results and in many cases, it provides graphical results.
  • 01:05 If you look at the screen shot on the right,
  • 01:07 you'll see the Minitab has two windows.
  • 01:10 The lower one is for
  • 01:11 data, the upper one is where the tabular results will be shown.
  • 01:15 Grass will be treated as a separate image that can be saved or copied and
  • 01:18 pasted into other files.
  • 01:20 Minitab is very compatible with Microsoft Excel.
  • 01:24 Data is normally entered in columns.
  • 01:26 The menu structure works in the same way as most Microsoft products
  • 01:30 like Excel works.
  • 01:31 In fact, you can directly copy and paste or import and
  • 01:35 export data between both Excel and Minitab.
  • 01:39 So let's see how Minitab would handle the descriptive statistics that
  • 01:42 we've been discussing in another module.
  • 01:45 First you have to watch out for one constraint.
  • 01:47 Minitab requires that the data always be organized in columns and
  • 01:52 with a column heading.
  • 01:53 You can't organize your data in rows.
  • 01:56 So let's see how we do descriptive statistics.
  • 01:59 Start by selecting Stat from the menu across the top.
  • 02:02 Stat is short for statistics.
  • 02:04 Then select the category of Basic Statistics.
  • 02:07 You can see that we have a lot of options here, but
  • 02:09 we'll select the first one, Display Descriptive Statistics.
  • 02:14 Okay, up until now it's similar to Excel.
  • 02:16 Now for a few of the little idiosyncrasies that are part of Minitab.
  • 02:21 When the window for selecting descriptive statistics pops up,
  • 02:24 we will need to select our data and the way we want our results displayed.
  • 02:29 First, highlight the column with your data in the window on the left side, and
  • 02:34 then click on Select.
  • 02:35 That column name should move to the Variables window.
  • 02:39 If there are no columns showing,
  • 02:40 just place your cursor in the Variables windows and click it.
  • 02:43 That tells Minitab what window you're trying to fill.
  • 02:47 Then click in the Statistics button, that will bring up a menu of items that you
  • 02:51 could display like Mean, Median, Standard Deviations, Skewness and Kurtosis.
  • 02:56 In fact, all the Excel items are there and a bunch more.
  • 03:00 After you click OK on that menu, click on the Graphs button.
  • 03:04 This will give you several options for how to display the graphs if you want one.
  • 03:08 Now click OK and Minitab will do the analysis and display it.
  • 03:13 By the way, although these are not in the defaults, I normally include Skewness and
  • 03:17 Kurtosis in the menu of Statistics.
  • 03:19 And I select Histogram of Data with Normal Curve in the Graphic selection.
  • 03:25 So let's see our results.
  • 03:27 The session window will provide the results of all the statistics
  • 03:30 that you calculated.
  • 03:32 These will be the same values that you would get with Excel, things like Mean,
  • 03:36 Median, Standard Deviation, Skewness and Kurtosis.
  • 03:39 And since we asked for it, we got a graph that shows the data values on a histogram
  • 03:43 and a normal curve plotted over the top of that data.
  • 03:47 So this example shows us that the data in this case is a normal distribution.
  • 03:52 But as you can see, Minitab is easy to use, and with just a few mouse clicks,
  • 03:57 it provides even more statistical capability than you have with Excel.
  • 04:02 That's not to say that we can't still use Excel.
  • 04:05 Pick the application that best fits you and your organization.
  • 04:09 I'll use both throughout this course.

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