Fundamentals of Statistics contains material of various lectures and courses of H. Lohninger on statistics, data analysis and here for more.

Exercise - Missing Values - Mineral Waters

As in many other countries, different brands of Austrian mineral water are labeled, including an excerpt of the chemical analysis of the water. The amount of the most important ions, such as wie sodium, potassium, calcium, magnesium, chloride, sulphate, and others, is printed on the labels. Suppose you have collected several of those labels, with one specific mineral water having no value for sodium on it. Try to estimate the content of sodium of this brand by establishing a (linear) multivariate model. The idea behind this approach is that some ions move parallel to some others (i.e. sodium will correlate to potassium, or hydrogencarbonate).

Use the data set MINWATER to estimate the content of sodium of the brand "Vöslauer". You may now go directly to the  DataLab    in order to experiment with the data.

Here is the available data for the brand "Vöslauer":

Ca             113.9
K                2.36
Mg              38.9
Cl              21.4
SO4            234.1
HCO3           266.6
solid residues 721.6