Consider an industrial experiment in which we have a sample of n = 10 fabrics
subjected to washing. The goal of the experiment is to analyze the performance of
a new experimental detergent for clothes. Specifically, the response variable under
study is the so called reflectance, that is the proportion of incident light which a given
surface (of fabric) is able to reflect, which can be considered a measure related to the
cleaning efficacy of the detergent. Suppose we wish to test, at the significance level
Table 1.1 Sample data of reflectance in the experiment on detergent performance.
Piece of fabric1 2 3 4 5
Reflectance 0.608 0.533 0.912 0.498 0.885
Piece of fabric6 7 8 9 10
Reflectance 0.291 0.805 0.436 0.868 0.721