Population Proportion Formula:
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The sample proportion (p̂) estimates the true population proportion based on sample data. It represents the fraction of successes in a sample and is used to make inferences about the entire population.
The calculator uses the sample proportion formula:
Where:
Explanation: The formula calculates the ratio of successes to total observations, providing an unbiased estimate of the population proportion.
Details: Sample proportion is fundamental in statistics for estimating population parameters, conducting hypothesis tests, and calculating confidence intervals for proportions.
Tips: Enter the count of successes (x) and total sample size (n). Both must be non-negative integers with x ≤ n. The result is a proportion between 0 and 1.
Q1: What's the difference between p and p̂?
A: p represents the true population proportion (unknown), while p̂ is the sample estimate of p.
Q2: How large should my sample be?
A: For reliable estimates, n should be large enough that both n*p̂ and n*(1-p̂) are ≥10 (rule of thumb).
Q3: Can p̂ be 0 or 1?
A: Yes, but these extreme values require special statistical methods for inference.
Q4: How accurate is p̂?
A: Accuracy depends on sample size - larger samples yield more precise estimates.
Q5: What if my sample isn't random?
A: Non-random samples may produce biased estimates that don't represent the population.