AP®︎ Statistics (pre-2026): Topic 6.2 Flashcards

An interval of plausible values for a population proportion based on sample data.

The inference procedure used to estimate one population proportion from one categorical sample.

Check randomization, independence with the 10% condition, and large counts for approximate normality.

Data must come from random selection or random assignment to justify inference assumptions.

When sampling without replacement, the sample size must be no more than 10% of the population.

The counts np-hat and n(1 minus p-hat) must both be at least 10.

The proportion of successes in the sample, used as the point estimate of p.

A single sample statistic used to estimate the corresponding population parameter.

The estimated standard deviation of p-hat, equal to sqrt[p-hat(1 minus p-hat)/n].

The z-score cutting off the middle C% of the standard normal distribution.

The long-run percent of similarly constructed intervals that capture the true parameter.

Construct p-hat plus or minus z-star times sqrt[p-hat(1 minus p-hat)/n].

Larger samples produce smaller standard errors and narrower confidence intervals.

Solve the margin of error formula for n using a guessed p-hat or 0.5.

Use 0.5 when no estimate is available to get the largest required sample size.

State the confidence interval as a range of plausible population proportions with proper units or labels.

The amount added and subtracted from p-hat, equal to z-star times its standard error.

The sample must have at least 10 successes and 10 failures for normality.