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Calculating sample size for Discrete data

How to Calculate Sample Size for Discrete Data: A Step-by-Step Guide

Learn how to manually calculate sample size for discrete data, ensuring precision and accuracy in your analysis. Follow these simple steps and examples to understand the process better.

Calculating Sample Size for Discrete Data: A Simplified Guide

Step 1: Estimate Defect Proportion (p)

Begin by estimating the proportion of defects in your process based on your knowledge of the process.

Step 2: Determine Required Precision (d)

Analyse the level of precision needed for your analysis.

Step 3: Calculate Minimum Sample Size

Use the formula: MSS = (2 / d)² x p x (1 – p) to find the minimum sample size needed.


If the defect proportion (p) is 10% and you require an accuracy of 1.5% (d = 0.015), then:

MSS = (2/0.015)² x 0.10 x (1 – 0.10) = 1600

Thus, the minimum sample size required for this example is 1600.

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