**Introduction**

The Confidence Interval Calculator is a handy tool that allows you to determine the range within which the true population mean is likely to fall, based on a sample mean, standard deviation, and a chosen confidence level. It’s a valuable resource for statisticians, researchers, and anyone dealing with data analysis.

**How to Use**

- Enter the sample mean (X).
- Choose the confidence level by selecting a percentage option.
- Input the standard deviation (s).
- Enter the number of samples (n).
- Click the “Calculate” button to find the confidence interval.

**Formula**

The confidence interval is calculated using the following formula:

$X±Z×n s $

Where:

- $X$ is the sample mean.
- $Z$ is the Z-score corresponding to the chosen confidence level.
- $s$ is the standard deviation.
- $n$ is the number of samples.

**Example**

Suppose you have a sample mean (X) of 50, a confidence level of 95%, a standard deviation (s) of 5, and 100 samples (n). The formula yields a confidence interval of $X±1.96×100 5 $, resulting in a confidence interval of 49.02 to 50.98.

**FAQs**

**What is a confidence interval?**

A confidence interval is a range of values within which the true population mean is likely to lie with a certain level of confidence.

**How do I choose the appropriate confidence level?**

Common confidence levels include 90%, 95%, and 99%. The choice depends on the desired level of certainty in your estimation.

**What is the Z-score, and how do I find it?**

The Z-score corresponds to the chosen confidence level and can be found using a standard normal distribution table or a calculator.

**Conclusion**

The Confidence Interval Calculator simplifies the process of estimating population parameters with a specified level of confidence. It provides valuable insights for decision-making, hypothesis testing, and drawing meaningful conclusions from your data.