Question

An independent t-test is used to test for:

Differences between means of groups containing different entities when the sampling distribution is normal, the groups have equal variances and data are at least interval.

Differences between means of groups containing different entities when the data are not normally distributed or have unequal variances.

Differences between means of groups containing the same entities when the data are normally distributed, have equal variances and data are at least interval.

Differences between means of groups containing the same entities when the sampling distribution is not normally distributed and the data do not have unequal variances.

Answer 1

Assumptions for the Independent Samples T Test

• Assumption of Independence: you need two independent, categorical groups that represent your independent variable. In the above example of test scores “males” or “females” would be your independent variable.
• Assumption of normality: the dependent variable should be approximately normally distributed. The dependent variable should also be measured on a continuous scale. In the above example on average test scores, the “test score” would be the dependent variable.
• Assumption of Homogeneity of Variance: The variances of the dependent variable should be equal.

considering the above choices it is:

Differences between means of groups containing different entities when the sampling distribution is normal, the groups have equal variances and data are at least interval.