Stats Reasoning Confidence Intervals Quiz

A sample size of n = 64 is drawn from a population whose standard deviation is σ = 5.6.

Find the margin of error for a 99% confidence interval for µ.

• 1.799

• 1.798

• 1.803

Tags

CCSS.HSS.IC.B.4

The lifetime of a certain type of batter is known to be normally distributed with a standard deviation of 20 hours. A sample of 50 batteries had a mean lifetime of 120.1 hours. It is desired to construct a 99% confidence interval for the mean lifetime of this type of battery.

What is the Confidence Interval to one decimal place?

• (114.5, 125.6)

• (112.8, 127.4)

• (112.82, 127.38)

• (114.56, 125.64)

Tags

CCSS.HSS.IC.B.4

If the 95% Confidence Interval for a population mean is (114.56, 125.54), then is it likely that the true population mean µ is greater than 130?

• Yes

• No

• Not enough information

• I have no idea what you're asking of me

Tags

CCSS.HSS.IC.B.4

A population has a standard deviation of σ = 17.3. How large of a sample must be drawn so that a 95% confidence interval for µ will have a Margin of Error equal to 1.4?

• 586.6

• 587

• 586

• 585

Tags

CCSS.HSS.IC.B.4

True or False:

The more confident you want to be, the smaller your confidence interval will be.

• True

• False

Tags

CCSS.HSS.IC.B.4

True or False:

The larger your confidence interval is, the more sure (higher confidence level) you can be.

• True

• False

Tags

CCSS.HSS.IC.B.4

A recent study of 750 Internet users in Europe found that 35% of Internet users were women.  What is the 95% confidence interval of the true proportion of women in Europe who use the Internet? 

• 0.321 < p < 0.379
• 0.316 < p < 0.384
• 0.309 < p < 0.391
• 0.305 < p < 0.395

Tags

CCSS.HSS.IC.B.4

What is the margin of error for the interval (6.8, 12.9)?

• 9.85

• 3.05

• 3.50

• 6.8

Tags

CCSS.HSS.IC.B.4

What is the point estimator for the interval (-5 , 13)?

• 10

• 9.5

• 9

• -5

Tags

CCSS.HSS.IC.B.4

What critical value t* is used in constructing a 99% confidence interval based on n = 12 randomly selected observations. 

• 3.106
• 3.055
• 2.58
• 1.96

Tags

CCSS.HSS.ID.A.4