the margin of error tells you how many percentage points your results will differ from the real population value 95% confidence interval with a 4 percent margin of error means that your statistic will be within 4 percentage points of the real population value 95%of the time the Margin of error can be calculated in two ways 1.Margin of error =Critical value ×Standard deviation 2. Margin of error = Critical value x standard error of the ststistic
