How many samples should be tested if a batch consists of 120 bottles of paracetamol suspension when the square root method is used?

How many samples should be tested if a batch consists of 120 bottles of paracetamol suspension when the square root method is used?

• A. 11
• B. 12
• C. 10
• D. 14

Answer: (B)

The square root method uses the batch size to determine how many units to sample, balancing inspection effort with the ability to detect problems. You take the square root of the total number in the batch to get a sense of a representative sample size. For a batch of 120 bottles, the square root is about 10.95. In practice, this method is used with a small safety margin, so you round up and add a bit to ensure adequate sampling. That approach gives 12 bottles to test. This choice reflects aiming for enough coverage to catch issues without inspecting every bottle. The other options are either a direct round (11) or numbers farther from the calculated guideline (10 or 14), but the convention used here prefers the conservative margin, hence 12.

The square root method uses the batch size to determine how many units to sample, balancing inspection effort with the ability to detect problems. You take the square root of the total number in the batch to get a sense of a representative sample size.

For a batch of 120 bottles, the square root is about 10.95. In practice, this method is used with a small safety margin, so you round up and add a bit to ensure adequate sampling. That approach gives 12 bottles to test.

This choice reflects aiming for enough coverage to catch issues without inspecting every bottle. The other options are either a direct round (11) or numbers farther from the calculated guideline (10 or 14), but the convention used here prefers the conservative margin, hence 12.