Q. Primary restriction of making demand?

The primary restriction of making demand forecasts lies in the fact that they are forecasts and hence their reliability is unknown. Most predicts are based upon a mix of historic information and expectations in relation to relevant influential variables. For instance the exchange rate predicts where the highest probability is attached to a rate of 1·54 Euro/£ is probable to be based on the statistical pattern of historic exchange rates including the standard deviation such that 1·54 Euro/£ constitutes the most frequently observed rate. This doesn't but necessarily means that the rate will be similar in the future - history doesn't always repeat itself.

Another restriction relates to the nature of the data being forecast. Weather forecasts are notoriously undependable because nature is such an uncontrollable force. Even if the UK climate has been hot on average for the past five years doesn't imply that this will be the case in the future. The factors which utter the weather are uncontrollable and consequently to a large degree unpredictable.

The forecast as well runs into problems because it seeks to link two unrelated variables. The state of the weather is completely independent of the exchange rate and vice versa as well as they can only be linked in the way suggested by the table if the range of alternative observations is restricted. This is eventually a distortion of a reality which is far more complex.