# Margins of error

A number calculated from a random sample that estimates the likely size of the sampling error in an estimate of a population parameter.

The margin of error is added to and subtracted from a point estimate of a population parameter to form a confidence interval for a population parameter, usually with a confidence level of 95%. The margin of error is therefore half of the width of a confidence interval.

Generally a larger sample size will give a smaller margin of error.

The higher the confidence level, the greater the margin of error.

Curriculum achievement objectives references

Statistical investigation: Level 8

Statistical literacy: Level 8