sample Response: The sample is from the right population, his customers. However, because he is surveying such a small number of people and only asking his best customers (who are probably the most satisfied, or they would not buy so much from him), the results are going to be biased, most likely positive, and not representative of his entire customer base.

What did you include in your response? Check all that apply.

The sample size is too small.
Only sending the survey to his best customers will yield biased results, most likely in the positive direction.
The sample is not representative of the entire population.