AP Statistics Calculator

The AP Statistics Calculator is a comprehensive tool that calculates essential statistical measures including mean, median, mode, standard deviation, variance, quartiles, skewness, kurtosis, z-scores, and percentile ranks. It's designed specifically for AP Statistics students and researchers.

Population data represents the entire group you're studying, while sample data is a subset of the population. The key difference is in variance calculation: population variance divides by n, while sample variance divides by n-1 (Bessel's correction) to provide an unbiased estimate.

This calculator uses standard statistical formulas and provides results rounded to 2 decimal places. All calculations follow AP Statistics curriculum standards and are suitable for academic and research purposes. Results are mathematically precise within floating-point limitations.

Skewness measures the asymmetry of data distribution: positive values indicate right skew, negative values indicate left skew, and zero indicates symmetry. Kurtosis measures the "tailedness" of the distribution: positive values indicate heavy tails, negative values indicate light tails.

Z-scores show how many standard deviations a data point is from the mean. Values between -2 and +2 are considered normal, between -2 and -3 or +2 and +3 are unusual, and beyond ±3 are outliers. This helps identify extreme values in your dataset.