Question: Principal Components Analysis

Let’s say you have analyzed a trivariate data base (three continuous variables) and have the following correlation matrix:

A. The two largest eigenvalues of | r – λI | = 0 are 1.68 and 0.83. What is the third value equal to? In general, how do we interpret eigenvalues?

B. The first two components are:


Are these elements correlations or direction cosines? What does this mean exactly?

C. What are the third components – the actual figures, or loadings, for this third eigenvector? [Hint: the signs of the elements of this third column are: (going down) -, +, +].