AP Statistics Flashcards: Biased and Unbiased Point Estimates
Written by AP Content Team, Verified for 2026 AP Exams, Last updated: May 2026
Review key ideas with interactive flashcards. This set includes 10 cards to help you master important concepts.
What property of an estimator allows it to be modeled using probability?
An estimator exhibits variability, and this variability can be modeled using probability.
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What property of an estimator allows it to be modeled using probability?
An estimator exhibits variability, and this variability can be modeled using probability.
If you use a sample proportion to estimate the population proportion, what role is the sample proportion playing?
The sample proportion is serving as a point estimator for the corresponding population parameter (the population proportion).
What is meant by the 'variability' of an estimator?
Variability refers to the spread or dispersion of the values of an estimator across different samples, which can be modeled with probability.
Describe the relationship between a sample statistic and a population parameter in the context of estimation.
A sample statistic is used as a point estimator to provide a single value estimate for its corresponding population parameter.
A simulation is run 1000 times, each time calculating a sample median. If the average of these 1000 medians is not equal to the population median, what can you conclude?
Based on this simulation, the sample median appears to be a biased estimator for the population median because its average value does not equal the population parameter.
How do you explain whether a particular sample statistic is an unbiased estimator?
You would explain that the estimator is unbiased if its average value across all possible samples is equal to the population parameter.
What is the defining characteristic of an unbiased estimator?
An estimator is unbiased if its average value equals the population parameter it is intended to estimate.
Why is it important to know if an estimator is biased or unbiased?
Knowing an estimator is unbiased confirms that, on average, it correctly targets the population parameter it is trying to estimate.
What is a point estimator?
A sample statistic that serves as a point estimator for the corresponding population parameter.
Define 'unbiased estimator'.
An estimator is considered unbiased if its average value is the same as the population parameter being estimated.