Chapter 4 · Sampling · Slide 146/274

What If the Population Is Small?

If the sample is larger than 10% of the population, corrections are necessary.

4.4 · Sample Size Special Case

For a margin of error of ± 1 % you would need:

n = (1 / 0.01)² = 100²

10.000

But what if the population comprises only 100 elements? (e.g. car manufacturers)

Rule of Thumb

If the sample is larger than 10% of the population, corrections are necessary.

Otherwise the formula overestimates the required size — the finite population reduces the actual sampling error.

Calculations show approximate values for a 95% confidence level

QUESTIONSTAR · Dr. Paul Marx 146 / 274