4/3/2013
Problem Session
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 and sample size calculations with Minitab
- Stat > Power and Sample Size
Power Activity
- By hand (see handout)
- With an applet
Please read Section 11.1 for class on Friday.