1.1 basic stats

definitions

• mode: value that occurs most frequently

• mean: average of the data set; x̄

• median: middle value in an ordered data set

• variance

  • measures entire distribution of data

  • how stretched out is data

  • s^2=\frac{\Sigma\left(x_{i}-\overline{x}\right)^2}{n-1}

• Standard deviation

  • measures variation from the mean

  • s=\sqrt{\frac{\Sigma\left(x_{i}-\overline{x}\right)^2}{n-1}}