Chapter 7: Confident Intervals and Sample Size

Point Estimate

Specific numerical value estimate of a parameter

Unbiased Estimator

Estimator with expected value equal to the parameter being estimated

Consistent Estimator

Estimator approaching the parameter as sample size increases

Relatively Efficient Estimator

Estimator with smallest variance among unbiased estimators

Interval Estimate

Range of values used to estimate a population parameter

Confidence Level

Probability that an interval estimate contains the parameter

Confidence Interval

Interval estimate of a parameter with a specific confidence level

Maximum Error of the Estimate (E)

Maximum likely difference between point estimate and actual parameter value

Rounding Rule

Guideline for decimal places when computing confidence intervals

t Distribution

Distribution for estimating mean with small sample size and unknown standard deviation

Degrees of Freedom (df)

Number of independent values in a statistical calculation

Population Proportion

Proportion of a characteristic in a population

Sample Proportion (
hat{p}
)

Proportion of a characteristic in a sample

Formula for Minimum Sample Size

Formula to determine necessary sample size for estimating mean or proportion

Critical Values

Values from a distribution defining the critical region