Population 1 has μ₁ = 70, σ₁ = 8. Population 2 has μ₂ = 65, σ₂ = 6. Independent samples of n₁ = 25 and n₂ = 36 are drawn.
What is the mean and standard deviation of the sampling distribution of x̄₁ − x̄₂?
- Acheck_circle
Mean 5; SD √(64/25 + 36/36) ≈ 1.92
- B
Mean 5; SD 8/√25 + 6/√36
- C
Mean 5; SD 14/√61
- D
Mean 0; SD 14
Explanation
Mean = μ₁ − μ₂ = 5. SD = √(σ₁²/n₁ + σ₂²/n₂) = √(64/25 + 36/36) = √(2.56 + 1) ≈ 1.92.