Final answer:
The question inquires if the standard deviation of fish numbers in a 20-gallon tank is two, which can be answered by comparing the calculated sample standard deviation to the claimed value.
Step-by-step explanation:
The question is asking whether the standard deviation of the number of fish in a 20-gallon tank is different from two, based on a sample data set provided. To determine this, we would typically calculate the sample standard deviation from the data given and compare it to the claimed standard deviation. However, without performing any calculation, it is not possible to confidently provide an answer in 200 words or less.
By computing the sample standard deviation, we could establish whether the real-world data supports or refutes the aquarist's claim of a standard deviation of two. This kind of statistical analysis is a common method used to address such questions and would provide insight into the variability of fish count in tanks of the same volume.