Question

One major reason that the two-sample t procedures are widely used is that they are quite robust. What does this mean? t procedures do not require that we know the standard deviations of the populations. Confidence levels and P-values from the t procedures are quite accurate even if the population distribution is not exactly Normal. t procedures compare population means, a comparison that answers many practical questions.

Answer 1

Confidence levels and P-values from the t procedures are quite accurate even if the population distribution is not exactly Normal

Explanation:

Confidence levels and P-values from the t procedures are quite accurate even if the population distribution is not exactly Normal

there is a general rule that depicts that T is okay to use when n >30. also when the sampling method for each sample is simple random sampling and samples are independent.