AP Statistics Flashcards: Interpreting p-Values
Written by AP Content Team, Verified for 2026 AP Exams, Last updated: May 2026
Review key ideas with interactive flashcards. This set includes 16 cards to help you master important concepts.
How does a p-value relate to the null distribution?
The p-value is the proportion of the null distribution that is as or more extreme than the observed test statistic.
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How does a p-value relate to the null distribution?
The p-value is the proportion of the null distribution that is as or more extreme than the observed test statistic.
What is the general formula for a standardized test statistic?
The standardized test statistic is calculated as (sample statistic - null value) / standard deviation of the statistic.
After calculating a z-statistic for a population proportion, what distribution would you use to find the p-value?
You would use a theoretical z-distribution, which serves as the null distribution for this test.
What does the phrase 'as or more extreme' signify in the definition of a p-value?
It signifies the probability of getting a result that provides at least as much evidence against the null hypothesis as the observed test statistic.
What two values are being compared in the numerator of the standardized test statistic formula?
The numerator compares the sample statistic (from the data) and the null value (from the null hypothesis).
What is the relationship between an observed test statistic and a p-value?
The p-value is the probability of obtaining the observed test statistic, or one more extreme, which is found by looking at the null distribution.
What is a p-value?
A p-value is the probability of obtaining a test statistic as or more extreme than the observed one, assuming the null hypothesis is true.
If a test statistic is far from the center of its null distribution, what can you generally infer about the p-value?
A test statistic far from the center is considered 'extreme,' which corresponds to a small p-value.
A researcher finds a p-value of 0.02 for a proportion test. How should they interpret this value?
Assuming the null hypothesis is true, there is a 2% probability of obtaining a test statistic as or more extreme than the one observed.
What is the primary goal of interpreting a p-value?
The primary goal is to assess the strength of the evidence provided by the data against the null hypothesis.
What fundamental assumption is made when interpreting a p-value for a one-sample proportion test?
The interpretation of a p-value for a one-sample proportion test assumes that the null hypothesis is true.
What is the null distribution of a test statistic?
The null distribution is the distribution of the test statistic assuming the null hypothesis is true, which can be a randomization or theoretical (e.g., z) distribution.
What specific test statistic is calculated for a population proportion?
The test statistic for a population proportion is a specific z-statistic.
Why is a p-value considered a conditional probability?
It is a conditional probability because its value is calculated under the condition that the null hypothesis is true.
Name two types of distributions that can be used as a null distribution.
The null distribution of a test statistic can be a randomization distribution or a theoretical distribution, such as a z-distribution.
What are the two key calculations performed in a significance test for a population proportion?
One must calculate an appropriate test statistic and then use it to find the corresponding p-value.