The formula to calculate the Discrepancy Rate (DR) is:
\[ DR = \frac{D}{I} \times 100 \]
Where:
Let's say you have 10 discrepancies in 500 impressions. Using the formula:
\[ DR = \frac{10}{500} \times 100 \]
We get:
\[ DR = 2 \% \]
So, the discrepancy rate is 2%.