If a radon measurement is calculated to be 7.8456 pCi/L, what number should be written on the report?

When reporting radon measurements, it is essential to adhere to established rounding conventions. The value 7.8456 pCi/L needs to be rounded to one decimal place for clarity and standardization in reports.

To perform this rounding, you consider the second decimal place, which is 4 in this case. Since the number following the first decimal place (8) is less than 5, you round down, meaning the first decimal place remains an 8. Consequently, the correct rounded measurement becomes 7.8 pCi/L.

This level of precision ensures that the data reported is both accurate and easily interpretable, maintaining consistency with regulatory and professional standards in radon measurement reporting.