1. What do you notice when you calculate probabilities associated with a sampling distribution?

As sample size increases, the probability is higher near the mean of the distribution.

As sample size increases, the probability is higher in the tails of the distribution.

As sample size increases, the probability is lower in the tails of the distribution.

As sample size increases, the probability is lower near the mean of the distribution.

2. A random sample of 125students is taken from the population of all part-time students in the United States, for which the overall proportion of females is 0.6.Calculate the probability that between 70 and 90 part-time students are female, inclusive. (3 decimal places)

3. If a population proportion is believed to be 0.45, how many items must be sampled to ensure that the sampling distribution of the sample proportion will be approximately normal?

4. If a population proportion is believed to be 0.55, how many items must be sampled to ensure that the sampling distribution of the sample proportion will be approximately normal?

5. A researcher studying public opinion of proposed Social Security changes obtains a simple random sample of 25 adult Americans and asks them whether or not they support the proposed changes. To say that the distribution of the sample proportion of adults who respond yes, is approximately normal, how many more adult Americans does the researcher need to sample if 22% of all adult American support the changes?

6. A researcher studying public opinion of proposed Social Security changes obtains a simple random sample of 25 adult Americans and asks them whether or not they support the proposed changes. To say that the distribution of the sample proportion of adults who respond yes, is approximately normal, how many more adult Americans does the researcher need to sample if 78% of all adult American support the changes?

7. What effect does the sample size have on the width of the confidence interval?

Changing the sample size has no effect on the width of the confidence interval.

Increasing the sample size will increase the width of the confidence interval.

Decreasing the sample size will decrease the width of the confidence interval.

Increasing the sample size will decrease the width of the confidence interval.

8. What effect does the margin of error have on the confidence interval?

Check all that apply.

Changing the margin of error has no effect on the confidence interval.

Increasing the margin of error will increase the width of the confidence interval.

Increasing the margin of error will decrease the width of the confidence interval.

Decreasing the margin of error will decrease the width of the confidence interval.

9. What is the critical value z-score for 94% confidence level?

Round answer to 2 decimal places.

10. What is the critical value z-score for 94% confidence level?

Round answer to 2 decimal places.

11. What is the critical value z-score for an 82% confidence level?

Round answer to 2 decimal places.

12. Ina recent health survey, 333 adult respondents reported a history of diabetes out of 3573 respondents. Construct a 90% confidence interval of the proportion of persons who reported a history of diabetes. (round to 3 decimal places) In form ( , )

13. Ina recent health survey, 333 adult respondents reported a history of diabetes out of 3573 respondents. Calculate the margin of error for a 90% confidence interval of the proportion of persons who reported a history of diabetes. (round to 3 decimal places)

14. Calculatethe minimum number of subjects needed for a research study regarding the proportion of respondents who reported a history of diabetes using the following criteria:

95% confidence, within 5 percentage points, and a previous estimate of 0.25

15. Calculatethe minimum number of subjects needed for a research study regarding the proportion of respondents who reported a history of diabetes using the following criteria:

95% confidence, within 5 percentage points, and a previous estimateis not known

16. Calculate minimum sample size needed to estimate the average salary earned by FSW alumni with the following criteria:

95% confidence level, sample standard deviation of $1525, and within $125.