Confidence Intervals

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

• 10

• 9.5

• 9

• -5

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

Which of the following changes to a study would result in a narrower confidence interval?

• increasing the confidence level, increasing the sample size
• decreasing the confidence level, decreasing the sample size
• increasing the confidence level, decreasing the sample size
• decreasing the confidence level, increasing the sample size.

Tags

CCSS.HSS.IC.B.4

A 90% confidence interval for the average salary of all CEOs in the electronics industry was constructed using the results of a random survey of 45 CEOs. The interval was ($139,048, $154,144). Give a practical interpretation of the interval.

• 90% of the sampled CEOs have salaries that fell in the interval $139,048 to $154,144
• We are 90% confident that the mean salary of all CEOs in the electronics industry falls in the interval $139,048 to $154,144. 
• 90% of all CEOs in the electronics industry have salaries that fall between $139,048 to $154,144
• We are 90% confident that the mean salary of the sampled CEOs falls in the interval $139,048 to $154,144.

Tags

CCSS.HSS.IC.B.4

The amount added and subtracted to the statistic.

• Margin of Error

• Confidence Interval

• Z Score

• Population

Tags

CCSS.HSS.IC.B.4

A research company wants to estimate the proportion of people who like oatmeal. They want the confidence level to be 95%. The company gets 325 people to sign up for the survey, but on the day that the survey is issued, only 250 people show up and take the survey. What happens to the confidence interval?

• It stays the same

• It gets narrower

• It gets wider

• Not enough information

Tags

CCSS.HSS.IC.B.4

Which of the following is the definition of a "point estimate?"

• The average of a population.

• The average of a sample.

• The midpoint of a confidence interval.

• The confidence interval.

Tags

CCSS.HSS.IC.B.4

A __________ gives an interval of plausible values for the _____________. 

• confidence interval, statistic
• point estimate, parameter
• point estimate, statistic
• confidence interval, parameter

Tags

CCSS.HSS.IC.B.4

What is the format for interpreting a confidence interval? 

• The interval from ___ to ___ captures the true mean in context.
• C% of samples of the same size taken from the same population will capture the parameter in question
• There is convincing evidence that C% gives the interval (___, ___) capturing the parameter in question.
• We are C% confident that the interval from ___ to ___ captures the [parameter in context].

Tags

CCSS.HSS.IC.B.4