Exam 1

1. Metainformation

   Tag	Value
   file	Inferential_Statistics_uu-Statistical-errors-800-en_uu-Statistical-errors-800-en
   name	uu-Statistical-errors-800-en
   section	Inferential Statistics/NHST/Statistical errors
   type	schoice
   solution	TRUE, FALSE, FALSE, FALSE
   Type	Conceptual
   Program
   Language	English
   Level	Statistical Literacy

   Question

   In a sample of girls, we found that they lost weight after 15 months ($M = −3.1$ kg). Using a statistical test, this difference in average weight is significant. What kind of statistical error may have occurred?

   
   
   1. TRUE: An error of the first kind: $H_0$ has been rejected, but there is actually no difference at all.
   2. FALSE: An error of the second kind: $H_0$ is not rejected, but there is a difference.
   3. FALSE: An error of the first kind: $H_1$ is assumed, but in real life the difference is much greater.
   4. FALSE: An error of the first and second kind can both: in statistical tests, you simply take the chance of making an error.
   
   

   Solution

   It is an error of the first kind: $H_0$ has been rejected, but there is really no difference at all.

   
   
   1. Indeed!
   2. It is concluded that the difference is significant. Being $H_0$ then rejected or not rejected?
   3. This is incorrect.
   4. This is incorrect.