Given that 4000 items are checked in one month, let the number of detective items be represented as y.
Quality control finds on average that 0.026% of the items in the factory are detective. This implies that
[tex]\text{Number of }\det ective\text{ items = }\frac{\text{0.026}}{100}\times\text{Total number of items checked}[/tex]When 4000 items are checked, we have the number of detective items to be evaluated as
[tex]\begin{gathered} \text{Number of }\det ective\text{ items = }\frac{\text{0.026}}{100}\times\text{Total number of items checked} \\ y=\frac{0.026}{100}\times4000 \\ \Rightarrow y=1.04 \end{gathered}[/tex]Hence, the number of detective items is 1.04.
