Decision Variables. The decision variables represent (unknown) decisions to be made. This
is in contrast to problem data, which are values that are either given or can be simply calculated
from what is given. For this problem, the decision variables are the number of notebooks to
produce and the number of desktops to produce. We will represent these unknown values by x1
and x2 respectively. To make the numbers more manageable, we will let x1 be the number of
1000 notebooks produced (so x1 = 5 means a decision to produce 5000 notebooks) and x2 be the
number of 1000 desktops. Note that a value like the quarterly prot is not (in this model) a decision
variable: it is an outcome of decisions x1 and x2.