minimili.blogg.se - Minitab boxplot

#MINITAB BOXPLOT HOW TO#
#MINITAB BOXPLOT SERIES#

The interpretation from dot plot are exactly same as that of histogram. What is dot plot in Minitab?ĭot plot is another way of making histogram in Minitab. Follow the command You can also make all other five interpretations as indicated above. Please refer the text box in the adjacent figure indicating (1) Bar: Value = 88, which is frequency and (2) Bin = 12.5, 7.5, which is class interval. Please take mouse on any bar and wait to see a small yellow text box. Please open given excel file ( Histogram-Data) and paste in the Minitab. Let us learn making histogram using Minitab. Relative to Specification - Defect percentage can be estimated by plotting LSL and USL on histogram.This is typically due to special cause in the process.

Presence of Outliers - Any value outside the normal data becomes distinctly visible in histogram.

This may be a special cause in the process or true nature of process itself.

Skew of Data - Histogram with long tail on either side is skew.

Spread is usually measured in terms of range and standard deviation. Histogram clearly gives estimation of spread of data.

Spread of Data - The distance of values from left end to right on X-axis indicate spread of data.

Based on process, it is termed as mean, median or mode of data. Center has highest frequency or is close to highest frequency value.

Center of Data - The value around which most of the data is accumulated is called center of data.

They are used to understand five distinct properties of data viz. Histograms is a X/Y graph having frequency on Y-axis and value of measurement of a continuous parameter on X-axis. The purpose and methods of analyzing data using these methods is detailed as follows: What is Histogram?

#MINITAB BOXPLOT SERIES#

We analyze one parameters for understanding behaviour of process by using (1) Histograms, (2) Box Plots and (3) Time Series Plots. Understanding relationship between multiple parameters.Analyzing one parameter (performance or control).What are the objectives of Graphical Analysis? It can only give direction for decision making and further analysis. Further details on hypothesis testing will be given in our subsequent articles.Ĭaution: Graphical analysis should never be used for concluding. Graphical analysis clearly indicates which alternate hypothesis is the best option. In this case, the risk of decision doubles compared to when alternate hypothesis is "less than" or "greater than". If graphical analysis is not used, the only option of alternate hypothesis is "not equal to". In the Hypothesis Testing, the alternate hypothesis can be any one of the three options viz. What is the basis of Alternate Hypothesis? If graphical analysis was not done the data will be collected in irrelevant ranges wasting our resources. For example, if graphical analysis indicates values are increasing, we need to collect data on higher side only for further validation of what is happening in process. We should direct our resources for further analysis based on graphical analysis.

#MINITAB BOXPLOT HOW TO#

How to decide direction of data collection? It allows all types of graphical presentation required for quick decisions. Minitab makes graphical analysis very simple. The purpose of graphical analysis is to have fair estimation of what is happening in the process apart from rationalizing resources and setting direction of decision making. What is the Purpose of Graphical Analysis?