Khan Academy on a Stick
Descriptive statistics
Measures of central tendency and dispersion. Mean, median, mode, variance, and standard deviation.

Statistics intro: Mean, median and mode
This is a fantastic intro to the basics of statistics. Our focus here is to help you understand the core concepts of arithmetic mean, median, and mode.

Finding mean, median and mode
Here we give you a set of numbers and then ask you to find the mean, median, and mode. It's your first opportunity to practice with us!

Exploring the mean and median
Watch as we use a nifty interactive module to demonstrate how moving points along a number line can help us find the mean and median.
 Comparing means of distributions
 Means and medians of different distributions

Inferring population mean from sample mean
Much of statistics is based upon using data from a random sample that is representative of the population at large. From that sample mean, we can infer things about the greater population mean. We'll explain.
Measures of central tendency
This is the foundational tutorial for the rest of statistics. We start thinking about how you can represent a set of numbers with one number that somehow represents the "center". We then talk about the differences between populations, samples, parameters and statistics.

Box and whisker plot
Is this some kind of cute cat video? No! Box and whisker plots seek to explain data by showing a spread of all the data points in a sample. The "whiskers" are the two opposite ends of the data. This video is more fun that a handful of catnip.

Constructing a box and whisker plot
Here's a word problem that's perfectly suited for a box and whiskers plot to help analyze data. Let's construct one together, shall we?

Constructing a box and whisker plot
Here's a word problem that's perfectly suited for a box and whiskers plot to help analyze data. Let's construct one together, shall we?

Finding the range and midrange
The range is the difference between the largest and smallest numbers. The midrange is the average of the largest and smallest number. Practice with this problem.
Boxandwhisker plots
Whether you're looking at scientific data or stock price charts, boxandwhisker plots can show up in your life. This tutorial covers what they are, how to read them and how to construct them. We'd consider this tutorial very optional, but it is a good application of dealing with medians and ranges.
 Range, variance and standard deviation as measures of dispersion

Variance of a population
Variance as a measure of, on average, how far the data points in a population are from the population mean

Sample variance
Thinking about how we can estimate the variance of a population by looking at the data in a sample.

Review and intuition why we divide by n1 for the unbiased sample variance
Reviewing the population mean, sample mean, population variance, sample variance and building an intuition for why we divide by n1 for the unbiased sample variance

Simulation showing bias in sample variance
Simulation by Peter Collingridge giving us a better understanding of why we divide by (n1) when calculating the unbiased sample variance. Simulation available at: http://www.khanacademy.org/cs/challengeunbiasedestimateofpopulationvariance/1169428428

Another simulation giving evidence that (n1) gives us an unbiased estimate of variance
Another visualization providing evidence that dividing by n1 truly gives an unbiased estimate of population variance. Simulation at: http://www.khanacademy.org/cs/unbiasedvariancevisualization/1167453164

Simulation providing evidence that (n1) gives us unbiased estimate
Simulation by KA user tetef showing that dividing by (n1) gives us an unbiased estimate of population variance. Simulation at: http://www.khanacademy.org/cs/willitconvergetowards1/1167579097
 Population standard deviation
 Sample standard deviation and bias

Statistics: Standard deviation
Review of what we've learned. Introduction to the standard deviation.

Exploring standard deviation 1 module
Ben Eater and Sal Khan talk through the Khan Academy Standard Deviation 1 Module: http://www.khanacademy.org/math/statistics/e/exploring_standard_deviation_1

Statistics: Alternate variance formulas
Playing with the formula for variance of a population.
Variance and standard deviation
We have tools (like the arithmetic mean) to measure central tendency and are now curious about representing how much the data in a set varies from that central tendency. In this tutorial we introduce the variance and standard deviation (which is just the square root of the variance) as two commonly used tools for doing this.

Statistics: The average
Introduction to descriptive statistics and central tendency. Ways to measure the average of a set: median, mean, mode

Statistics: Variance of a population
Variance of a population.

Statistics: Sample variance
Using the variance of a sample to estimate the variance of a population
Sal's old statistics videos
This tutorial covers central tendency and dispersion. It is redundant with the other tutorials on this topic, but it has the benefit of messy handwriting and a cheap microphone. This is Sal circa 2007 so take it all with a grain of salt (or just skip it altogether).