Two independent samples: n₁ = 100 from population with p₁ = 0.5; n₂ = 200 from population with p₂ = 0.4.
What is the standard deviation of p̂₁ − p̂₂?
- A
≈ 0.005
- Bcheck_circle
≈ 0.060
- C
≈ 0.10
- D
≈ 0.030
Explanation
SD = √(0.5·0.5/100 + 0.4·0.6/200) = √(0.0025 + 0.0012) = √0.0037 ≈ 0.060.