Unit 6 - One Proportion Z Interval Practice

What is the critical z value for a 98% confidence interval?

• 1.645

• 1.96

• 2.33

• 2.58

What is the critical z value for a 95% confidence interval?

• 1.645

• 1.96

• 2.33

• 2.58

What is the critical z value of a 99% confidence interval?

• 1.645

• 1.96

• 2.33

• 2.58

For a set confidence level and value of p-hat and (1 - p-hat), which of the following would reduce the margin of error?

• Smaller sample size

• Larger sample size

If you want to decrease the margin of error (make the interval smaller), which is a valid option?

• Increase confidence level

• Decrease confidence level

• Reduce the sample size

• Take a stratified random sample

Tags

CCSS.HSS.IC.B.4

Which pair of changes would decrease the size of your margin of error?

• Increase confidence, increase sample size

• Decrease confidence, increase sample size

• Increase confidence, decrease sample size

• Decrease confidence, decrease sample size

Tags

CCSS.HSS.IC.B.4

A 2007 survey of 980 American drivers concluded that 38% of the driving population would be willing to pay higher gas prices to protect the environment. Which is the best explanation of the poll having a margin of error of 3%

• 3% of those surveyed refused to respond

• It would not be unexpected for 3% of the population to readily agree to the higher gas prices

• Between 343 and 402 of the 980 drivers who responded would be willing to pay more for the environment

• If a similar survey of 980 American drivers was taken weekly, a 3% change would expected

• It is likely that between 35% and 41% of the driving population would be willing to pay more for gas

Tags

CCSS.HSS.IC.B.4

A 2007 survey of 980 American drivers concluded that 38% of the driving population would be willing to pay higher gas prices to protect the environment. What is the value of n?

• 2007

• 980

• 0.38

• 38

• This information was not given

Tags

CCSS.7.SP.A.1

CCSS.HSS.IC.A.1

A 2007 survey of 980 American drivers concluded that 38% of the driving population would be willing to pay higher gas prices to protect the environment. What is the value of p-hat?

• 2007

• 980

• 38

• 0.38

• p-hat is the true proportion of drivers who would agree with a price increase, but the value is unknown

Tags

CCSS.HSS.IC.B.4

A 2007 survey of 980 American drivers concluded that 38% of the driving population would be willing to pay higher gas prices to protect the environment. What is the value of p?

• 2007

• 980

• 38

• 0.38

• p is the true proportion of drivers who are fine with the increase, but we do not know the actual value.

Tags

CCSS.HSS.IC.B.3