Where futures are being used to hedge a commodities position, which of the following formulae...

When using a futures contract to hedge a position, the correct way to determine the number of futures contracts to use is to use the following formula. This adjusts for the 'tailing the hedge' adjustment required as a result of the daily settlement feature of futures contracts.

Minimum Variance Hedge Ratio x Dollar Value of Position / Dollar Value of Single Futures Contract

When using forward contracts to hedge a position, no adjustment to tail the hedge is required (as settlement happens only at the end), and the number of units of the exposure when compared to the number of units per contract should be used. The formula in the case of forward contracts is:

Minimum Variance Hedge Ratio x Units in Position Held / Units in Single Futures Contract

In practice however, the difference between the above two formulae is de-minimis; and for the exam you should be okay to use either of the above two to determine the number of contracts - unless the question is directed to testing your knowledge of the 'tailing the hedge' adjustment.