AP Statistics Flashcards: Confidence Intervals for the Difference of Two Proportions
Written by AP Content Team, Verified for 2026 AP Exams, Last updated: May 2026
Review key ideas with interactive flashcards. This set includes 11 cards to help you master important concepts.
What is an interval estimate based on a confidence interval for a difference of proportions?
It is the calculated range of plausible values for the true difference between two population proportions, often with specified units.
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What is an interval estimate based on a confidence interval for a difference of proportions?
It is the calculated range of plausible values for the true difference between two population proportions, often with specified units.
What two conditions must be verified before calculating a confidence interval for a difference between population proportions?
To calculate the confidence interval, one must check for the independence of the samples and the approximate normality of the sampling distribution.
What two key components make up the confidence interval formula for the difference of two proportions?
The formula is comprised of the point estimate (p1-hat - p2-hat) and the margin of error (z* * SE).
A political analyst wants to estimate the true difference in voter support for a candidate between two districts. What statistical method should be used?
The analyst should calculate a two-sample z-interval to find a confidence interval for the difference between the two population proportions.
What is the appropriate confidence interval procedure for a comparison of population proportions?
The appropriate procedure is a two-sample z-interval for a difference between population proportions.
If you need to create an interval estimate with specific units for a difference in proportions, what tool should you use?
You should use a confidence interval for a difference in proportions, as it can be used to calculate such interval estimates.
What are the three main steps for creating a confidence interval for a comparison of population proportions?
The three steps are: identify the appropriate procedure (two-sample z-interval), verify conditions (independence and normality), and calculate the interval.
A medical researcher calculates a confidence interval for the difference in the proportion of patients responding to two different drugs. How is this result used?
The confidence interval is used to provide an interval estimate for the true difference in the effectiveness of the two drugs.
What is the general formula for calculating an interval estimate for a comparison of proportions?
The interval estimate is calculated using the formula: (p1-hat - p2-hat) ± z* * SE.
Identify the specific statistical test name for a two-sample comparison of proportions.
The specific procedure is a two-sample z-interval.
What does the (p1-hat - p2-hat) part of the confidence interval formula represent?
This term represents the point estimate, which is the observed difference between the two sample proportions.