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Central Limit Theorem (CLT) Simulation

Created:November 5, 2024
Last Updated:August 7, 2025

This interactive simulation demonstrates the Central Limit Theorem (CLT), one of the most important concepts in statistics. The CLT states that when independent random samples are taken from any population distribution, the distribution of sample means will approximate a normal distribution as the sample size increases. This simulation allows you to explore this phenomenon by selecting different underlying distributions, adjusting sample sizes, and observing how the sampling distribution of means evolves. Whether you're a student learning statistics or a practitioner wanting to visualize this fundamental theorem, this tool provides an intuitive understanding of how the CLT works in practice.

Simulation

Click the "Start Simulation" button to start the simulation. The simulation will run until you stop it. You can also click the "Quick Demo" to generate 500 samples quickly and view the results instantly.

5100
SlowFast
Samples Collected
0
Population μ
0.000
Sample Means μ
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Current Sample x̄
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⏸️ Paused
Sample Means μ: ---
Should equal population μ
Sample Means σ: ---
Observed standard error
Expected σ (σ/√n): 0.0000
Theoretical standard error

Learn More

Understanding the Central Limit Theorem

Key Concepts

1. Sample Means

The mean of repeated random samples taken from a population. The CLT describes how these sample means are distributed.

2. Sample Size

The number of observations in each sample (nn). Generally, the CLT begins to apply when n30n \geq 30, though this may vary depending on the underlying distribution.

3. Normal Distribution

The limiting distribution of sample means, characterized by its bell shape and symmetric properties.

4. Standard Error

The standard deviation of the sampling distribution, calculated asσn\frac{\sigma}{\sqrt{n}} where σ\sigma is the population standard deviation.

Mathematical Foundation

For a population with mean μ\mu and standard deviation σ\sigma, if we take samples of size nn, then as nn increases:

XˉN(μ,σn)\bar{X} \sim N(\mu, \frac{\sigma}{\sqrt{n}})

Where:

  • Xˉ\bar{X} is the sampling distribution of means
  • μ\mu is the population mean
  • σ\sigma is the population standard deviation
  • nn is the sample size