Six Sigma Green Belt

Answer: A - This level of significance is also referred to as a Type I error.

Key Takeaway: A Type I error is said to be the risk of rejecting the null hypothesis when it is true. In other words, it is the probability that the researcher will conclude that there are significant differences between samples or populations when there are none. For example, if a researcher concluded that those in their 20s purchase different cars than those in their 30s when there are no statistically significant differences, then the researcher has committed a Type I error.