L23 · Reason about random samples

1. 1.

   A population mean is unknown. Sample means from samples of size 100 tend to vary. Which sample size would you expect to give a sample mean closer to the population mean: 10 or 100?

   Answer. 100

   Larger random samples tend to have sample means closer to the population mean.

2. 2.

   A population mean is unknown. Sample means from samples of size 100 tend to vary. Which sample size would you expect to give a sample mean closer to the population mean: 10 or 100?

   Answer. 100

   Larger random samples tend to have sample means closer to the population mean.

3. 3.

   A population mean is unknown. Sample means from samples of size 100 tend to vary. Which sample size would you expect to give a sample mean closer to the population mean: 10 or 100?

   Answer. 100

   Larger random samples tend to have sample means closer to the population mean.

4. 4.

   A population mean is unknown. Sample means from samples of size 100 tend to vary. Which sample size would you expect to give a sample mean closer to the population mean: 10 or 100?

   Answer. 100

   Larger random samples tend to have sample means closer to the population mean.

5. 5.

   A population mean is unknown. Sample means from samples of size 10 tend to vary. Which sample size would you expect to give a sample mean closer to the population mean: 10 or 100? Then Luis needs 4 of that amount. What is the total they need?

   Answer. 400

   Larger random samples tend to have sample means closer to the population mean. Then multiply by 4: 400.

6. 6.

   A population mean is unknown. Sample means from samples of size 100 tend to vary. Which sample size would you expect to give a sample mean closer to the population mean: 10 or 100? Then Jonah needs 5 of that amount. What is the total they need?

   Answer. 500

   Larger random samples tend to have sample means closer to the population mean. Then multiply by 5: 500.

7. 7.

   A population mean is unknown. Sample means from samples of size 100 tend to vary. Which sample size would you expect to give a sample mean closer to the population mean: 10 or 100? Then Nora needs 3 of that amount. What is the total they need?

   Answer. 300

   Larger random samples tend to have sample means closer to the population mean. Then multiply by 3: 300.

8. 8.

   A population mean is unknown. Sample means from samples of size 10 tend to vary. Which sample size would you expect to give a sample mean closer to the population mean: 10 or 100? Then Ava needs 4 of that amount. What is the total they need?

   Answer. 400

   Larger random samples tend to have sample means closer to the population mean. Then multiply by 4: 400.

9. 9.

   A population mean is unknown. Sample means from samples of size 100 tend to vary. Which sample size would you expect to give a sample mean closer to the population mean: 10 or 100? Then Malik needs 3 of that amount. What is the total they need?

   Answer. 300

   Larger random samples tend to have sample means closer to the population mean. Then multiply by 3: 300.

10. 10.

    A population mean is unknown. Sample means from samples of size 25 tend to vary. Which sample size would you expect to give a sample mean closer to the population mean: 10 or 100? Then Jonah needs 5 of that amount. What is the total they need?

    Answer. 500

    Larger random samples tend to have sample means closer to the population mean. Then multiply by 5: 500.

11. 11.

    Think

    Ava tried this problem:
    A population mean is unknown. Sample means from samples of size 100 tend to vary. Which sample size would you expect to give a sample mean closer to the population mean: 10 or 100?
    Ava wrote -100. That is not correct. What is the right answer?

    Answer. 100

    Ava’s answer -100 is off. Larger random samples tend to have sample means closer to the population mean.

12. 12.

    Think

    Luis tried this problem:
    A population mean is unknown. Sample means from samples of size 10 tend to vary. Which sample size would you expect to give a sample mean closer to the population mean: 10 or 100?
    Luis wrote 99. That is not correct. What is the right answer?

    Answer. 100

    Luis’s answer 99 is off. Larger random samples tend to have sample means closer to the population mean.

Original extra practice. Keys are computed from the items, not guessed.