4/10/2023
Hypothesis Testing  A decision rule based on data

Null Hypothesis 
True 
False 
Decision 
Reject Null Hypothesis 
Type I Error 
Correct Decision 
Do Not Reject Null Hypothesis 
Correct Decision 
Type II Error 
Computing Type II error probabilities
 Example  Let p equal the proportion of defective components in a very large shipment sent to a computer company. The company accepts the shipment only if Ho: p =0.1 can be rejected in favor of Ha: p < 0.1 at a significance level of 0.05 based on a sample of 100 components.
 Compute the probability of failing to reject Ho when the actual percentage of defectives is 7%.
 Compute the probability of failing to reject Ho when the actual percentage is 8%.
 Would the probability of failing to reject Ho increase or decrease if the actual percentage is 9%? Explain your response. (Hint: compare the two probabilities you computed above.)
Power Activity
Power and sample size calculations with R
 Download, install, and explore with the pwr package.
 See Power.R to compute the power on the handout with R
 Explore with the pwr package to compute other powers.
Please complete your reading of Chapter 7 for class on Wednesday.
We will have our second exam on Friday.