The large sample z test for μ₁ − μ₂ can be used as long as at least one of the two sample sizes, n₁ and n₂, is greater than or equal to 30.

Question

Quizplus · Accepted Answer

The large sample z test for the difference between two means (μ1 - μ2) assumes that both sample sizes (n1 and n2) are large (typically n ≥ 30) to ensure the sampling distribution of the difference is approximately normal, not just one of the samples.

The Large Sample Z Test for μ1 − μ2 Can

The Large Sample Z Test for μ₁ − μ₂ Can