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
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Using the mean, median and mode to try to represent data

Example: Finding mean, median and mode
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Mean Median and Mode

Sample mean versus population mean.
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The conceptual and notational differences between a parameter for a population and a statistic calculated from a sample.
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.

Reading BoxandWhisker Plots
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Reading BoxandWhisker Plots

Constructing a boxandwhisker plot
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Constructing a box and whisker plot to analyze data.

BoxandWhisker Plots
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BoxandWhisker Plots

Example: Range and midrange
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Range and Midrange
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
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Variance of a population
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Variance as a measure of, on average, how far the data points in a population are from the population mean

Sample variance
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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
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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
 Population standard deviation
 Sample standard deviation and bias

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

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

Statistics: Variance of a Population
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Variance of a population.

Statistics: Sample Variance
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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).