---
url: "https://questionstar.com/principles-of-survey-research/chapter-4/slide-143.html"
title: "z-Values and Maximum Margin of Error"
type: "lehrbuch-slide"
chapter: 4
chapterTitle: "Sampling"
slide: 143
---

# z-Values and Maximum Margin of Error

*With z = 1.96 and the maximum π = 0.5 the formula simplifies to:*

z-Values

1.96 for 95 % confidence level

2.58 for 99 % confidence level

Maximum Margin of Error for 95% Confidence Level

With **z = 1.96** and the maximum **π = 0.5** the formula simplifies to:

![E = z · √(π(1−π)/n) = 1.96 · √(0.5(1−0.5)/n) ≈ 1/√n](/principles-of-survey-research/media/formel_max_fehler.png)

… the upper bound of the error — independent of the actual proportion π.

---

*Slide 143 of 274 · Chapter 4: Sampling · Principles of Survey Research · Dr. Paul Marx*