Example 1: Measures of dispersion: compare error, median absolute deviation (mad), mean squared error (variance), and root mean squared error (standard deviation) in estimating the data set points by the mean. (Do a simple example by hand using data 4, -1, 3, 0, -1.)
Example 2: Compute measures of spread for the simple example using R (var, sd, IQR, mad)
Example 3: Compare measures of spread for the faithful data. Also display using a histogram (hist) and boxplot (boxplot).
The hand computation is the actual or population value. What happens when you only have a sample of the data?