It appears that you might be referring to a situation in which Welch's t-test can be applied. Since it would be excruciating to write the required formulae here on answers.com let me refer you to the wikipedia page.
Chat with our AI personalities
Its a statistic, they guess. A good guess, but they still do.
Dependent variable is the variable that can be measured. However, the independent variable is the variable that changes in the two groups.
The Independent Samples T Test compares the mean scores of two groups on a given variable.
same as one way anova population variance equal among groups noramlly distributed independent samples
You define groups by selecting non-overlapping subsets of the domain which, together, cover the whole domain. For each group you combine responses for all units whose domain element (explanatory or independent variable) falls within the group.