Question

what is the commonly used significance level (a) threshold in hypothesis testing? a. 0.01 b. 0.05 c. 0.5 d. 0.1

Explanation:

In hypothesis testing, the significance level ($\alpha$) represents the probability of rejecting the null hypothesis when it is actually true (Type - I error). A significance level of 0.05 is a widely - accepted standard. It strikes a balance between being too lenient (higher $\alpha$ like 0.5 would lead to many false rejections) and too strict (lower $\alpha$ like 0.01 might miss real effects).

Answer:

B. 0.05