Question

2. Briefly explain the meaning of the t-test for regression analysis. How can the “rule of two” be used to evaluate t-ratios?

Answer 1

test

-test is a small sample test. It was developed by William Gosset in 1908. He public te published test under the pen name of "Student". Therefore, it is known as Student's t-test For

t-test is a small sample test. It was developed by William Gosset in 1908. For applying t-test the value of t-statistic is computed.The following formula is used

               t= Deviation from the population parameter/Standard error of the sample statistic

Calculated value of t is compared with table value of t for given degrees of freedom at certain specified level of significance. Applications/Uses of t-test:

1) Test of hypothesis about the population

2) Test of hypothesis about the difference between the two means in case of independent samples

3) Test of hypothesis about the difference between two means with dependent samples

(4) Test of hypothesis is about an observed coefficient of correlation.

The t test is an inferential statistic: it goes beyond mere description, and allows the investigator to make inferences, or judgments, about the magnitude of a difference, or some other relationship, between two groups or variables. There are several varieties of the t test, all based on the same logic of comparing the difference between two means to their standard error(s).

As a general rule of thumb, if two group means differ from each other by more than 2 standard deviations, we consider that this is rather unlikely to have occurred simply by chance. This heuristic is known as the rule of two standard deviations.