Recall that an absolute vale is how far away a value is from zero. A value can in the positive or negative range. With this question. an absolute value is helpful because it allows the actual value to be within a specific range based on the amount of error.
For example, let's take two scenarios. One scenario is when there is more jars produced in one day, possible from a human error. The other scenario is when a few jars were damaged in the process. In both scenarios, the actual value is going to be different than the expected value. However, using the absolute value function allows the company to make sense of both scenarios, even though one will be in the negative range.