**Hi everyone, In Reading 11 " Sampling and Estimation" 's Practice problems, I encountered a question which I can’t understand:**

[question removed by moderator]

Does anybody understand why:

- P(2σ)=0.0456
**NOT**P(2σ)= 0.0228**CUZ according to normal table (z)**1 - P(2σ) = 1 - 0.9772 P(3σ)=0.0026**NOT**P(3σ)= 0.0013**CUZ according to normal table (z)**1 - P(3σ) = 1 - 0.9987 - P(|X−μ|≥2σ)≤(1/2)2=0.2500
**and**P(|X−μ|≥3σ)≤(1/3)2=0.1111.**What is question B asking ? and what is the specific meaning of the answer ?**