Given the following data

Period

Actual

Demand

Forecast

$\backslash$table$[[1,2000,1900],[2,2130,1980],[3,1990,2040],[4,2280,2190],[5,2050,2100]]$

which of the following is true

The forecast is always within plus$/$minus $88$ units from the actual demand

On average, the forecast is $120$ units away from the actual demand

On average, the forecast is $88$ units away from the actual demand

On average, the forecast is overestimating the actual demand by $20$ units

On average, the forecast is underestimating the actual demand by $200$ units