Notice that the last requirement of Cornerstone 3.4 asks us to compute the materials handling cost for the year, not for a month.
Since monthly data were used to determine the cost formula, fixed cost must be multiplied by 12 to get the fixed cost for the year instead of the month.
If the materials handling cost for the quarter were desired, then fixed cost would be multiplied by three (the number of months in a quarter). If weekly data had been used to determine the cost formula.
the fixed cost for the year would be the weekly fixed cost multiplied by 52, the number of weeks in a year.