Confidence intervals are important in statistics.
This chapter provides information on how such intervals can be constructed from samples, and how to interpret such intervals. Remember that the Central Limit Theorem of Statistics states that the means of sample means of a specific size are normally distributed. When we read the results of polls in newspapers and magazines produced by reliable polling organizations, we are often provided with a margin of error. The margin of error actually determines the length of the confidence interval. That is, we want the margin of error to be no more than 1.5 units.