Quiz-Understanding Margin of Error and Confidence Intervals

A 99% confidence interval for a population mean is (100, 200). What is the margin of error?

• 50

• 100

• 150

• 200

Tags

CCSS.HSS.IC.B.4

If a 90% confidence interval for a population proportion is (0.4, 0.6), what is the sample proportion?

• 0.1

• 0.3

• 0.5

• 0.7

• Not enough information to determine.

Tags

CCSS.HSS.IC.B.4

CCSS.HSS.IC.A.1

• 1.64

• 1.96

• 2.33

• 2.58

Tags

CCSS.HSS.ID.A.4

A survey estimates that 45% of voters favor candidate A with a margin of error of 4%. What is the confidence interval for the proportion of voters who favor candidate A?

• (0.41, 0.49)

• (0.39, 0.51)

• (0.43, 0.47)

• (0.45, 0.49)

Tags

CCSS.HSS.IC.B.4

CCSS.HSS.IC.A.1

CCSS.HSS.ID.A.4

To decrease the margin of error in a confidence interval, you should:

• Increase the confidence level

• Decrease the sample size

• Increase the sample size

• Decrease the confidence level

Tags

CCSS.HSS.IC.B.4

If the margin of error in a confidence interval is 8 and the sample mean is 200, what is the lower bound of the confidence interval?

• 192

• 196

• 200

• 208

Tags

CCSS.HSS.IC.B.4

What does a 95% confidence level mean in the context of constructing a confidence interval?

• There is a 95% chance the sample data is correct.

• 95% of the sample data lies within the interval.

• We are 95% confident that the interval (in context) contains the population parameter.

• We are 95% confident that the sample parameter estimates the population statistic.

Tags

CCSS.HSS.IC.B.4

CCSS.HSS.IC.A.1

If you want to construct a confidence interval with a smaller margin of error without changing the sample size, what could you do?

• Increase the confidence level

• Decrease the confidence level

• Increase the variability in the sample

• Decrease the variability in the sample

Tags

CCSS.HSS.IC.B.4

What is the effect of increasing the confidence level on the width of the confidence interval?

• It decreases the width of the confidence interval.

• It increases the width of the confidence interval.

• It has no effect on the width of the confidence interval.

• It first increases then decreases the width of the confidence interval.

Tags

CCSS.HSS.IC.B.4

How does decreasing the standard deviation of the sample data affect the margin of error in a confidence interval?

• It increases the margin of error.

• It decreases the margin of error.

• It has no effect on the margin of error.

• It first decreases then increases the margin of error.

Tags

CCSS.HSS.IC.B.4