Question

Discuss how you would respond and how you would explain the purpose of the t test and significance in this case.

Answer 1

>>A t-test is generally used to compare means of two or more populations or compare the mean of one population from a standard value.

>>A t-test is used when the population variance is unknown. but this can be estimated from the sample taken from the population.

>>A t -statistic is computed which is then compared with some threshold value to decide the significance of the t-statistic and the result of the test. Roughly higher the t-statistic value higher is the significance of the test. (For example threshold value of t is 1.96 at 5% level of significance)

>> T-test follows a t-distribution which depend upon a variable named the degree of freedom of the distribution, Note for a higher degree of freedom a t-distribution approaches a normal distribution. Thus when we have larger data points we conduct a z-test instead of a t-test