Question

What is the relationship between the alpha level, the size of the critical region, and the risk of a type i error?

Answer 1

Alpha level is a probability value that is used to define the concept of "very unlikely" in a hypothesis. This value determines he boundaries for the critical region, which is composed of the extreme sample values that are very unlikely to be obtained if the null hypothesis is true. Type I error is when a researcher rejects a true null hypothesis.
The relationship between the alpha level, the size of the critical region, and the risk of a type i error is the following: when the alpha level increases, the critical region increases and type I error increases.