CDPH Lead Inspector/Assessor California State Practice Exam

If the total number of similar dwellings is 600, how many dwellings should be sampled?

1. 25

2. 26

3. 27

4. 28

The correct answer is: 26

To determine the number of dwellings to sample from a total of 600 similar units, one commonly used method is to apply a statistical sampling formula. For a population size of 600, the generally recommended sampling size aligns with statistical principles that account for variability and confidence levels. In various lead inspection guidelines, including those pertinent to California certification, it is typically advised to sample a percentage of the total population to achieve a representative assessment of lead risk. According to standard recommendations, for populations of around 600, a sample size of approximately 26 is appropriate. This number balances statistical reliability with practical sampling efforts, ensuring that the sample is large enough to provide useful data without being excessively cumbersome. Using 26 dwellings allows for sufficient representation, given that it's statistically sound while recognizing the resources and time constraints that inspectors may face. Thus, when considering these factors, the choice of 26 for sampling makes sense and aligns with established practices designed to optimize the identification of lead hazards in similar dwelling units.