EXHIBIT $4$

Yellow Wings Paragliding uses different forecasting methods to plan the number of jumps in each

month. The table below provides the number of jumps that were recorded from January to June, as well

as the forecasts using exponential smoothing and three months moving average calculated by the

company.

Please calculate the average forecast error $(\frac{?}{\text{b}\text{a}\text{r}}(E))$ for both forecasts for the period January to

June. What is the best forecast method based on the $\frac{?}{\text{b}\text{a}\text{r}}(E)$ criterion? $($round your results to $2$

decimals$)$

A$.$ Exponential smoothing forecast

B$.3$ months moving average

C$.$ Both are equally good

D$.$ This measure does not allow to compare these two forecasts

Please calculate the MAD for both forecasts for the period January to June. What is the best

forecast method based on this criterion? $($round your results to $2$ decimals$)$

A$.$ Exponential smoothing forecast

B$.$ Both are equally good

C$.3$ months moving average

D$.$ This measure does not allow to compare these two forecasts

What is the MAD for the exponential smoothing method in the period January to June?

A$.$ Less than $15$

B$.15-19\mathrm{.}9$

C$.20-29\mathrm{.}9$

D$.30$ or moreEXHIBIT $4$

Yellow Wings Paragliding uses different forecasting methods to plan the number of jumps in each

month. The table below provides the number of jumps that were recorded from January to June, as well

as the forecasts using exponential smoothing and three months moving average calculated by the

company.

Please calculate the average forecast error $(\frac{?}{\text{b}\text{a}\text{r}}(E))$ for both forecasts for the period January to

June. What is the best forecast method based on the $\frac{?}{\text{b}\text{a}\text{r}}(E)$ criterion? $($round your results to $2$

decimals$)$

A$.$ Exponential smoothing forecast

B$.3$ months moving average

C$.$ Both are equally good

D$.$ This measure does not allow to compare these two forecasts

Please calculate the MAD for both forecasts for the period January to June. What is the best

forecast method based on this criterion? $($round your results to $2$ decimals$)$

A$.$ Exponential smoothing forecast

B$.$ Both are equally good

C$.3$ months moving average

D$.$ This measure does not allow to compare these two forecasts

What is the MAD for the exponential smoothing method in the period January to June?

A$.$ Less than $15$

B$.15-19\mathrm{.}9$

C$.20-29\mathrm{.}9$

D$.30$ or more