A Type I error is defined as the following. 1- rejecting a false null hypothesis 2- rejecting a true null hypothesis 3- failing to reject a false null hypothesis 4- failing to reject a true null hypothesis Solution Defintion of Type-I error: A type I error, also known as an error of the first kind, occurs when the null hypothesis (H0) is true, but is rejected. hence the answer will be 2) rejecting a true null hypothesis..

1. A Type I error is defined as the following.
1- rejecting a false null hypothesis
2- rejecting a true null hypothesis
3- failing to reject a false null hypothesis
4- failing to reject a true null hypothesis
Solution
Defintion of Type-I error: A type I error, also known as an error of the first kind,
occurs when the null hypothesis (H0) is true, but is rejected. hence the answer will be 2)
rejecting a true null hypothesis.