ap stats unit 6 vocab a

Point estimator

A statistic that provides an estimate of a population parameter.

Point estimate

The value of a point estimator from a sample.

Confidence interval

Gives a set of plausible values for a parameter based on sample data.

Interval estimate

Another name for Confidence Interval.

Confidence level C

Gives the approximate percentage of confidence intervals that will capture the population parameter in a repeated random sampling with the same sample size.

Conditions for Constructing a Confidence Interval (Fill in the blank.)

Random, 10%, Large Counts

Random

The data come from a random sample from the population of interest.

10%

When sampling without replacement, n < 0.10N.

Large Counts

Both np^ and n(1 – p^) are at least 10.

Margin of error

(of an estimate) Describes how far, at most, we expect the point estimate to vary from the population parameter

Critical value

A multiplier that makes the interval wide enough to have the stated capture rate.

Standard error of p^

An estimate of the standard deviation of the sampling distribution of p^.

z*

Critical Value variable

One-sample z interval for a proportion

A confidence interval used to estimate a population proportion p.

Margin of error (formula)

z*(square root ((p^(1 – p^))/n))

Sample size for desired margin of error

z*(square root ((p^(1 – p^))/n)) where p^ is a guessed value for the sample proportion. The margin of error will always be less than or equal to ME if you use p^ = 0.5.