Geometric waiting times

STA 112. Practice questions, not past papers.

Lessons

• Count trials through the first success
• Moments, tails and lack of memory

Practice questions

1. Here a geometric random variable counts what?

   Statistics study edition practice item Q156; Source: T87, S37-40, S44-45

2. For that geometric convention, the mean is what?

   Statistics study edition practice item Q157; Source: T87, S37-40, S44-45

3. Which property is associated with a geometric waiting time?

   Statistics study edition practice item Q158; Source: T87, S37-40, S44-45

4. Changing from trials to failures before success changes variance how?

   Statistics study edition practice item Q159; Source: T87, S37-40, S44-45

5. Independent trials have success probability 0.25. Find the probability that the first success occurs on trial 3. Give the value to 4 decimal places.

   Statistics study edition practice item Q160; Source: T87, S37-40

6. Independent trials have success probability 0.2. Find the probability that the first success occurs on trial 4. Give the value to 4 decimal places.

   Statistics study edition practice item Q161; Source: T87, S37-40

7. Independent trials have success probability 0.5. Find the probability that the first success occurs on trial 2. Give the value to 4 decimal places.

   Statistics study edition practice item Q162; Source: T87, S37-40

8. A geometric trial count has p=0.25. Find its variance. Give the value to 4 decimal places.

   Statistics study edition practice item Q163; Source: T87, S38-40

9. The trial-count geometric support begins at _____.

   Statistics study edition practice item F051; Source: T87, S37-40, S44-45

10. The geometric waiting-time model has the _____ property.

    Statistics study edition practice item F052; Source: T87, S37-40, S44-45

Topic gap report