To determine whether there was a significant difference
between the average waste generation per working day in the
two periods a contrast of hypothesis was carried out. This test
allows us to know if the differences between two samples are real
or, expressed in other terms, the differences are not a chance
occurrence and therefore they belong to different populations. It
also allows us to know the opposite effect, that is, whether the differences
are so small that they are a chance occurrence and therefore
both samples belong to the same population