http://support.minitab.com/en-us/minitab/17/topic-library/modeling-statistics/multivariate/principal-components-and-factor-analysis/what-is-pca/
http://setosa.io/ev/principal-component-analysis/
A consumer products company wants to analyze customer responses to several characteristics of a new shampoo: color, smell, texture, cleanliness, shine, volume, amount needed to lather, and price. They perform a principal components analysis to determine whether they can form a smaller number of uncorrelated variables that are easier to interpret and analyze. The results identify the following patterns:
- Color, smell, and texture form a "Shampoo quality" component.
- Cleanliness, shine, and volume form an "Effect on hair" component.
- Amount needed to lather and price form a "Value" component.