A well-established research company conducts a random survey of 5241 people asking whether or not they like Coffee Brand X. The company determines that only 18% of respondents like Coffee Brand X. The research company publishes their findings in a peer-reviewed statistics journal.

Question

The company that makes Coffee Brand X conducts their own survey. The coffee company calls 20 people who recently purchased Coffee Brand X, asking whether or not they like Coffee Brand X. The company determines that 9 out of 10 people like Coffee Brand X, and they publish their findings on the company website.

Which of the following statements is true regarding these surveys?
A.
The coffee company's survey is likely to be biased based on the sample method and size.

B.
The research company's survey is likely to be flawed as so few people selected the coffee brand.

C.
There must have been a calculation error in one of the surveys for the survey results to be so different.

D.
The results of both surveys are valid even though different sample methods and sample sizes were used.

Answer 1

The correct statement regarding these surveys is:

A. The coffee company's survey is likely to be biased based on the sample method and size.

This is true because the coffee company conducted a survey with a very small sample size (only 20 people) who were all recent purchasers of Coffee Brand X, which could lead to a biased representation of the general population's opinion about the brand. In contrast, the research company surveyed a much larger and randomly selected sample of 5241 people, which is likely to provide a more reliable estimate of the general sentiment towards Coffee Brand X.