The accounting department is now evaluating a potential project and an analyst is calculating the Operating Cash Flow for the project, which of the following statements are correct?$$

I$)$ Since depreciation is a non$-$cash item, an error in the depreciation calculation would not affect the final result.

II$)$ If the variable cost per unit is overstated, the OCF will be under$-$estimated.

III$)$ If the cash balance is overstated in the calculation, the OCF will be under$-$estimated.

IV$)$ If fixed costs are omitted, the OCF will be over$-$estimated.