Margin of Error
95% Confidence
The margin of error is a statistical term that indicates the range within
which the true value of a population parameter lies, based on a sample taken from that population.
It reflects the level of uncertainty or potential error in the results of a survey or experiment.
For example, if a poll reports a margin of error of Β±3%, and 50% of respondents support a particular
candidate, the true support level in the entire population is likely between 47% and 53%.
The margin of error accounts for the variability that arises from sampling only a portion of the
population rather than conducting a complete census.
The 95% confidence level is a common standard used in statistical analysis to express the degree of certainty that a sample's estimate is close to the true population parameter. When a margin of error is reported with a 95% confidence level, it means that if you were to take multiple random samples from the population and calculate the margin of error for each sample, about 95% of those margins would contain the true population value.
In practical terms, if a poll shows that 50% of respondents support a candidate with a margin of error of Β±3% at a 95% confidence level, you can be 95% confident that the true support level for the candidate in the entire population lies between 47% and 53%. The confidence level reflects the likelihood that the interval calculated from the sample will cover the true population parameter, acknowledging that there is a 5% chance that it will not.
