Confidence Intervals

When interpreting the confidence interval, make sure that you are describing the 

• statistic
• parameter

Tags

CCSS.HSS.IC.B.4

What is the format for interpreting a confidence interval? 

• The interval from ___ to ___ captures the point estimate.

• 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 true [parameter in context] is between _____ and _____

Tags

CCSS.HSS.IC.B.4

The purpose of a confidence interval is to

• Find out the mean of a sample

• Determine the exact value of a population parameter

• Estimate the value of a population parameter

• Determine whether or not your sample data is accurate.

Tags

CCSS.HSS.IC.B.4

A confidence interval gives all plausible values of the population parameter you are trying to estimate

• TRUE

• FALSE

• I HAVE NO IDEA

Tags

CCSS.HSS.IC.B.4

The general form of a confidence interval is

• point estimate x 2

• point estimate + margin of error

• point estimate - margin of error

• point estimate +/- margin of error

Tags

CCSS.HSS.IC.B.4

Given a confidence interval, how do you determine the value of the point estimate?

• Find the middle of the interval - (lower value + upper value)/2.

• Find the range of the interval and divide by 2.

• Use the lower end of the interval.

• You can't determine the point estimate from the confidence interval.

Margin of Error is equal to:

• high end - low end

• Point Estimate

Tags

CCSS.HSS.IC.B.4

An IQ test was given to a simple random sample of 75 students at a certain college. The sample mean score was 105.2. I want to construct a 95% confidence interval for the mean IQ scores of all students at the college.

What is the point estimate?

• 75

• 105.2

• 10

• 0.90

Tags

CCSS.HSS.IC.B.4

If a proposed value of the population parameter is not captured in the confidence interval, there is convincing evidence that that proposed value is incorrect.

• TRUE

• FALSE

Tags

CCSS.HSS.IC.B.4

A local pizza shop claims that they deliver pizzas in 30 minutes or less. The 95% confidence interval obtained from a random sample of 12 deliveries is [26.8,41.0].

Calculate the point estimate used to create this interval.

• 7.1 minutes

• 13.4 minutes

• 33.9 minutes

• 30.7 minutes

Answer explanation

(26.8 + 41)/2 = 33.9

Tags

CCSS.HSS.IC.B.4