AP Stats Inference Method

The value of that statistic from a sample is called a point _______________ .

True or False: A confidence interval gives an interval of plausible values for a parameter based on sample data.

• True

• False

True or False: The confidence interval C gives the overall success rate of the method used to calculate the confidence interval. That is, the interval computed from the sample data will capture the true parameter value in C% of all possible samples when the conditions for inference are met.

• True

• False

To interpret a C% confidence interval for an unknown parameter, say...

• “We are C% confident the answer is (parameter in context)."

• "We are C% the true parameter will be ___."

• "We are C% confident that the interval from ____ to _____ captures the (parameter in context)."

The ______________________ of an estimate describes how far, at most, we expect the estimate to vary from the true population value. That is, in a C % confidence interval, the distance between the point estimate and the true parameter value will be less than the margin of error in C % of all samples.

• sample size

• margin of error

• confidence level

• confidence interval

True or False: Notice that we don’t need an actual sample to interpret the confidence level. Interpreting the confidence level is about describing the method for calculating a confidence interval, not about interpreting a specific confidence interval calculated from an actual sample.

• True

• False

Select all the ways to calculate a confidence interval...

• point estimate ± margin of error

• statistic ± (critical value)(standard deviation of statistic)

To make sure the formula for a one-sample z interval for a population proportion is valid, we need to verify that the observations in the sample can be viewed as independent and that the sampling distribution of pˆ

is approximately Normal. To do this you need to check these conditions:

• Random

• 10%

• Same Probability

• Large Counts

If you are asked to create and interpret a confidence interval you must complete all four steps for full credit. Which shows the correct order of steps?

• Conclude, State, Do, Plan

• Plan, Do, State, Conclude

• Do, State, Plan, Conclude

• State, Plan, Do, Conclude

You can use your calculator to calculate a confidence interval.

• True

• False