# Confidence Interval

## Definition of Confidence Interval

Confidence Interval: A range of values that is calculated based on sample statistics and is used to measure how accurate a prediction made by a model is likely to be.

## What is a Confidence Interval used for?

Confidence Interval is a tool used to measure how confident we are in a particular statistic. It is typically expressed as a percentage, and is calculated by dividing the number of events that occur within the confidence interval by the total number of events. A confidence interval indicates the likelihood that an event will happen again given similar conditions. In other words, it tells us how reliable a sample statistic is likely to be when applied to a larger population or data set. A higher confidence interval suggests that an event is more likely to happen again than it would with a lower confidence interval. For example, if you have an 90% confidence interval, then there is a 90% chance that if you were to repeat your experiment or survey with different people, you would get similar results. Additionally, Confidence Intervals can be used to compare two groups and see if their results differ significantly from each other. When comparing two groups with different samples sizes or different sampling strategies, you can use the confidence intervals to help make inferences about the difference between those groups. This can help researchers determine if any differences observed between them are statistically significant or simply due to random variation in the samples studied.