Title: Confidence Interval Definition
Headings: Confidence Interval
Confidence Interval
What Is Confidence Interval?
Key Takeaways
Understanding Confidence Interval
Calculating Confidence Interval
Frequently Asked Questions
What Does a Confidence Interval Reveal?
How Are Confidence Intervals Used?
What's a Common Misconception About Confidence Intervals?
What Is a T-test?

Content: Confidence level refers to the percentage of probability, or certainty, that the confidence interval would contain the true population parameter when you draw a random sample many times. How Are Confidence Intervals Used? Statisticians use confidence intervals to measure uncertainty in a sample variable. For example, a researcher selects different samples randomly from the same population and computes a confidence interval for each sample to see how it may represent the true value of the population variable. The resulting datasets are all different where some intervals include the true population parameter and others do not. What's a Common Misconception About Confidence Intervals? The biggest misconception regarding confidence intervals is that they represent the percentage of data from a given sample that falls between the upper and lower bounds. In other words, it would be incorrect to assume that a 99% confidence interval means that 99% of the data in a random sample falls between these bounds. What it actually means is that one can be 99% certain that the range will contain the population mean. What Is a T-test?