Quiz--Confidence Interval and Margin of Error

If the margin of error in a confidence interval is 4, what is the range of the confidence interval around a sample mean of 50?

• 46 to 54

• 48 to 52

• 45 to 55

• 49 to 51

Tags

CCSS.HSS.IC.B.4

What does a 99% confidence level imply about a confidence interval compared to a 95% confidence level?

• The margin of error is smaller.

• The confidence interval is narrower.

• The margin of error is larger.

• The confidence interval is the same width.

Tags

CCSS.HSS.IC.B.4

If you increase the confidence level from 90% to 95%, what happens to the margin of error?

• It decreases.

• It stays the same.

• It increases.

• It becomes zero.

Tags

CCSS.HSS.IC.B.4

How does decreasing the sample size from 150 to 100 affect the margin of error in a confidence interval, assuming all else remains constant?

• The margin of error decreases.

• The margin of error increases.

• The margin of error stays the same.

• The margin of error becomes zero.

Tags

CCSS.HSS.IC.B.4

A 95% confidence interval for a population mean is calculated as 45 ± 2. What is the sample mean?

• 43

• 45

• 47

• 44

Tags

CCSS.HSS.IC.B.4

What is the effect of increasing the sample size on the width of the confidence interval, assuming the confidence level remains the same?

• The width of the confidence interval increases.

• The width of the confidence interval decreases.

• The width of the confidence interval stays the same.

• The width of the confidence interval doubles.

Tags

CCSS.HSS.IC.B.4

For a given confidence level, if the margin of error is 3 and the sample mean is 50, what is the lower bound of the confidence interval?

• 47

• 53

• 50

• 49

Tags

CCSS.HSS.IC.B.4

What happens to the confidence interval if the standard deviation of the population decreases, assuming all other factors remain constant?

• The confidence interval becomes wider.

• The confidence interval becomes narrower.

• The confidence interval remains unchanged.

• The confidence interval inverts.

Tags

CCSS.HSS.IC.B.4

CCSS.HSS.ID.A.4

A confidence interval for the mean score of a test is (75, 85). What is the margin of error?

• 5

• 10

• 15

• 20

Tags

CCSS.HSS.IC.B.4

What can be inferred about the relationship between confidence level and margin of error?

• Increasing the confidence level decreases the margin of error.

• Increasing the confidence level increases the margin of error.

• The confidence level and margin of error are not related.

• Decreasing the confidence level decreases the margin of error.

Tags

CCSS.HSS.IC.B.4