SAS for Statistics

There are plenty of websites are explaining about SAS software so here i just want to explain simply how to do Statistical Analysis out of SAS.

my first topic is:

How to test Normality for a sample data in SAS:

Normal Distribution in SAS:

Problem:

In a manufacturing company produced some ball bearings from a new machine. The following are the weight of ball bearings in a day. How to check the weights are following normal distribution?

Solution:

Step: 1

Open SAS

Step: 2

In editor window type the following codes:

data weight_club;
input Weight;

datalines;
165
124
135
123
143
121
123
123
;
proc univariate data = weight_club
Normal;
var weight;
probplot/normal(mu=est sigma=est);
histogram/normal;
run;


Step : 3

Use the run button in toolbar to execute the code

Thats it. you will get no of pages of results in output window. now the critical part is to interpret the results.

All pages of output were important to understan the data. but simply if you want to know the normality is exist in the sample then just click the page Test for Naormality, you will get the follwoing result:

Shapiro - Wilk test statistic and P values for Shapiro - Wilk, Kolmogrov-smirnov, Cramer-von Mises and Andersen-Darling.

as per the practical situation we will consider any one of the above test. generally we will consider Andersen-Darling.

for the above sample test statistic is 0.922 and P value is 0.0097 which is resulting the sample is not following Normal distribution.