How to find Type 2 Error and Power of a Significance Test by Hand

For the probability of a Type 2 Error

• Step 1: know what significance level you want, then find the critical values
• Step 2: find the z-score or t-score using
• (alternative value - value from null hypothesis)/(standard deviation from sample or population / sqrt(n))
• the p-value of the z or t-score is the probability of a Type 2 Error

To find the power, use this equation

• 1 - probability of a Type 2 Error