Use the following sales data $($Note: the same data set is provided in the first worksheet of the exam Excel file$)$ to answer the question:

t Demand

$1300$

$2600$

$3400$

$4500$

$5250$

What will be the mean error and mean absolute deviation $($calculated based on all four in$-$sample forecasts$)$ if forecasts are calculated using the last period demand technique?