1.0 INTRODUCTION
The t-test was developed by W. S. Gossett, a statistician employed at the Guinness brewery. However, because the brewery did not allow employees to publish their research, Gossett's work on the t-test appears under the name "Student". The t-test is sometimes referred to as "Student's t-test." Gossett was a chemist and was responsible for developing procedures for ensuring the similarity of batches of Guinness. The t-test was developed as a way of measuring how closely the yeast content of a particular batch of beer corresponded to the brewery's standard.
And the same statistical methodology that compares a particular batch of beer to a standard can be used to compare how different any two batches are from each other. The test can be used to compare the yeast content of two kegs of beer brewed at separate times. Extending this into the realm of social phenomena, this methodology was used to address questions such as whether SAT preparation courses improve test scores or not and one of the advantages of the t-test is that it can be applied to a relatively small number of cases. It was specifically designed to evaluate statistical differences for samples of 30 or less. 2.0 DEFINITION OF T-TEST A t-Test is any statistical hypothesis test in which the test statistics follows a Student’s t distribution if the null hypothesis is supported.
3.0 A BRIEF EXPLANATION
One of the most commonly used statistical procedures is the t-test. There are actually three variations of the t-test that we will consider. These are the single-sample, two samples with different groups and the two- sample with the same group.
3.1 SINGLE-SAMPLE T-TEST
Single Sample t-test involves one group. The single sample t-test is used to describe the nature of the population confidence intervals or compare the group mean to a specified value. To establish confidence intervals, the mean and the standard error of the mean are calculated and the confidence intervals are