- Minitab Cookbook
- Isaac Newton
- 328字
- 2021-07-16 12:29:24
Using probability plots to check the distribution of two sets of data
We will use the probability plot tool to check if data from two suppliers could be normally distributed. The results are stacked in the second column, Length
, where the first column, Supplier
, informs us which supplier the result comes from. Probability plots from the graph menu allow more options than the normality test in the basic statistics tools. Using the probability plot, we can generate a chart for each supplier.
How to do it…
The following instructions will generate a probability plot for the results of two suppliers:
- Go to the File menu and select Open Worksheet….
- Click on the button labeled Look in Minitab Sample Data folder.
- Open the
Camshaft2.MTW
worksheet. - Go to the Graph menu and select Probability Plot….
- Select the Single graph option.
- Enter
Length
as the graph variables. - Select the Multiple Graphs… button and then select the By Variables tab in the new subdialog.
- Enter
Supplier
into the section labeled By variables with groups in separate panels:. - Click on OK in each dialog box to create the graphs.
How it works…
The Single chart option that we selected by default creates a probability plot of the columns entered into the graph variables. The Length
column, though, is divided into two suppliers. To allow us to check if both suppliers A and B could follow a normal distribution, we have to split the chart. The options for multiple graphs allow us to split the graph into separate panels on one page, as the previous instructions show, or to create a new page for each level of the supplier column.
There's more
The Probability plots… option has more flexibility than just checking if data could be distributed normally. Within the graph dialog using options under the Distribution… button, we can change the type of distribution to be used and enter historical data for that distribution.
- INSTANT Citrix XenDesktop 5 Starter
- Citrix XenApp? 7.5 Desktop Virtualization Solutions
- 中國特色社會主義國家審計制度研究
- 國家治理能力視角的國家審計功能理論研究
- 項目管理(第二版)
- Learning Informatica PowerCenter 9.x
- Microsoft System Center Data Protection Manager 2012 SP1
- 非線性經濟關系的建模
- Team Foundation Server 2013 Customization
- 中國政府統計問題研究
- 《企業內部控制基本規范》合規實務指南
- Programming Microsoft Dynamics NAV(Fifth Edition)
- 內審兵法
- Getting Started with Oracle Tuxedo
- 內部審計情景案例:理解審計行為,辨析審計決策