Hypotheses, errors and decisions

STA 121. Practice questions, not past papers.

Lessons

• Set the question before the test
• Interpret errors, power and p-values

Practice questions

1. A Type I error occurs when what happens?

   Statistics study edition practice item Q254; Source: T104-108

2. Test power equals what?

   Statistics study edition practice item Q255; Source: T104-108

3. A p-value is calculated assuming what?

   Statistics study edition practice item Q256; Source: T104-108

4. For a two-sided z test at 5%, rejection occurs when what holds?

   Statistics study edition practice item Q257; Source: T104-108

5. At a specified alternative, Type II error probability β=0.2. Find power. Give the value to 4 decimal places.

   Statistics study edition practice item Q258; Source: T108

6. At a specified alternative, Type II error probability β=0.35. Find power. Give the value to 4 decimal places.

   Statistics study edition practice item Q259; Source: T108

7. At a specified alternative, Type II error probability β=0.1. Find power. Give the value to 4 decimal places.

   Statistics study edition practice item Q260; Source: T108

8. Rejecting a true H0 is a Type _____ error.

   Statistics study edition practice item F084; Source: T104-108

9. Power equals one minus _____.

   Statistics study edition practice item F085; Source: T104-108

10. If β=0.2, test power is _____.

    Statistics study edition practice item F086; Source: T104-108

Topic gap report