How to determine if a sample is small or large? In my homework, the sample size is 66. The answer in my book says that it's a small sample? But how do I know that? Thanks!

Note:

Hey there! Thank you for posting the question! Sometimes a sample cannot be determined as a small sample or large sample only based on its size. We have explained the situations of determining a sample as small or large.

Conditions for a sample to determine it as large sample or small sample:

• In some books the rule of thumb for a sample to consider it as large sample is n>30. That is, if the sample size is greater than or equal to 30 then that sample will be considered as large sample and if the sample size is less than 30 then that sample will be considered as small sample. But this rule of thumb might change based on the scenario.
• If the distribution of a sample is symmetric and uni-modal without any outliers, then the sample size of 15 can also be considered as large sample.
• If the distribution of a sample is moderately skewed and uni-modal without outliers, then its sample size should be between 16 and 40 to consider it as large sample.
• If a sample has extreme and many outliers then it will not be considered as large sample, even though its size is greater than 40.
• The sample should be a good representative of the population. That is, population size also matters in determining a sample as small or large.