Khan Academy
Khan Academy: Statistics: Pearson's Chi Square Test (Goodness of Fit)
Video gives an example of the step by step process of using a Pearson's chi-square test to accept or reject a hypothesized data distribution. [11:48]
Khan Academy
Khan Academy: Statistics: Calculating R Squared
Video shows using a spreadsheet to demonstrate calculating the coefficient of determination or r-squared. Also explains how to interpret the value of r-squared. [9:45]
Khan Academy
Khan Academy: Statistics: R Squared or Coefficient of Determination
Video reviews the basics of the regression line, then shows how the formula for the coefficient of determination or r squared is derived. Explains how to interpret the coefficient of determination. [12:41]