Checking for statistical significance when testing a new marketing channel ensures:

• A. That the marketing channel will always increase sales.
• B. That all confounding variables have been eliminated.
• C. That observed results are unlikely to have occurred by random chance alone.
• D. That the sample size is the largest possible.

Answer: (C)

Verified step by step guidance

1. Understand the concept of statistical significance: Statistical significance is a measure of whether the observed results in a study are unlikely to have occurred due to random chance. It does not guarantee causation or eliminate confounding variables.
2. Identify the purpose of testing a new marketing channel: The goal is to determine if the observed results (e.g., increased sales) are meaningful and not due to random variation in the data.
3. Clarify the role of confounding variables: Statistical significance does not imply that all confounding variables have been eliminated. Confounding variables are external factors that can influence the results, and their control requires careful experimental design.
4. Recognize the importance of sample size: While larger sample sizes can improve the reliability of results, statistical significance focuses on the probability of results occurring by chance, not the size of the sample.
5. Conclude the correct interpretation: Statistical significance ensures that the observed results are unlikely to have occurred by random chance alone, which is the correct answer to the problem.