between events can be positive or negative. Negative
association shows that the more of one event, the less
of the other, while positive association shows
the more of one event, the more of the other.
To determine if
two events are associated, statisticians sometimes
use a mathematical technique known as a chi-square
tool for organizing information
or numbers is a matrix.
Matrices look like rectangular tables but typically do
not use lines to frame each cell.
Information that places something in a given
categorysuch as eye coloris
called categorical data. Information that can
be ordered on a number linesuch as heightis
called quantitative data.