13. Using standard deviations for the values obtained in parts a, b, and c of problem 12, compare

your results to the results of a Cumberland Company survey of its managers concerning the

accuracy of the company's forecasts (shown below).

Expected Forecast Error for a Period of:

1 Month 1 Quarter 1 Year

Level of Detail

Total Volume

Family

Type in Family

Grade in Type

SKU

*+12%.

*NF no forecast.

*Stockkeeping unit.

12*

15

15

30

8

10

NF+

NF

8

8

12

NF