The T-tests are performed to compute the confidence limits for one sample or two independent samples by comparing their means and mean differences. The SAS procedure named PROC TTEST is used to carry out t tests on a single variable and pair of variables.

Syntax

The basic syntax for applying PROC TTEST in SAS is −

PROC TTEST DATA = dataset;
VAR variable;
CLASS Variable;
PAIRED Variable_1 * Variable_2;

Following is the description of the parameters used −

Dataset is the name of the dataset.
Variable_1 and Variable_2 are the variable names of the dataset used in t test.

Example

Below we see one sample t test in which find the t test estimation for the variable horsepower with 95 percent confidence limits.

PROC SQL;
create table CARS1 as
SELECT make, type, invoice, horsepower, length, weight
FROM
SASHELP.CARS
WHERE make in ('Audi','BMW')
;
RUN;
proc ttest data = cars1 alpha = 0.05 h0 = 0;
var horsepower;
run;

When the above code is executed, we get the following result −

sas 59

Paired T-test

The paired T Test is carried out to test if two dependent variables are statistically different from each other or not.

Example

As length and weight of a car will be dependent on each other we apply the paired T test as shown below.

proc ttest data = cars1 ;
paired weight*length;
run;

When the above code is executed, we get the following result −

sas 60 1

Two sample t-test

This t-test is designed to compare means of same variable between two groups.

Example

In our case we compare the mean of the variable horsepower between the two different makes of the cars(“Audi” and “BMW”).

proc ttest data = cars1 sides = 2 alpha = 0.05 h0 = 0;

title "Two sample t-test example";

class make;

var horsepower;

run;

When the above code is executed, we get the following result −

sas 61

So, this brings us to the end of blog. This Tecklearn ‘How to perform T-Tests in SAS’ blog helps you with commonly asked questions if you are looking out for a job in SAS. If you wish to learn SAS and build a career in Data Analytics domain, then check out our interactive, SAS Training for SAS BASE Certification Training, that comes with 24*7 support to guide you throughout your learning period. Please find the link for course details:

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What you will Learn in this Course?

Introduction to SAS

Introduction to SAS
Installation of SAS
SAS windows
Working with data sets
Walk through of SAS windows like output, search, editor etc

SAS Enterprise Guide

How to read and subset the data sets
SET Statement
Infile and Infile Options
SAS Format -Format Vs Informat

SAS Operators and Functions

Using Variables
Defining and using KEEP and DROP statements
Output Statement
Retain Statement
SUM Statement

Advanced SAS Procedures

PROC Import
PROC Print
Data Step Vs Proc
Deep Dive into Proc

Customizing Datasets

SAS Arrays
Useful SAS Functions
PUT/INPUT Functions
Date/Time Functions
Numeric Functions
Character Functions

SAS Format and SAS Graphs

SAS Format statements
Understanding PROC GCHART, various graphs, bar charts: pie, bar

Sorting Techniques

NODUP
NODUKEY
NODUP Vs NODUKEY

Data Transformation Function

Character functions, numeric functions and converting variable type
Use functions in data transformation

Deep Dive into SAS Procedures, Functions and Statements

Find Function
Scan Function
MERGE Statement
BY Statement
Joins
Procedures Vs Function
Where Vs If
What is Missover
NMISS
CMISS

PROC SQL

SELECT statement
Sorting of Data
CASE expression
Other SELECT statement clauses
JOINS and UNIONS

Using SAS Macros

Benefits of SAS Macros
Macro Variables
Macro Code Constituents and Macro Step
Positional Parameters to Macros

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