Quartile Calculator
Calculate the three quartiles (Q1, Q2, Q3), the interquartile range (IQR), and outlier fences for a normal distribution based on the mean and standard deviation.
Quartiles divide a data set into four equal parts.
For a Normal Distribution:
- Q1 = μ - 0.6745σ (25th percentile)
- Q2 = μ (50th percentile / median)
- Q3 = μ + 0.6745σ (75th percentile)
- IQR = Q3 - Q1 = 1.349σ
Outlier Detection:
- Lower fence = Q1 - 1.5 × IQR
- Upper fence = Q3 + 1.5 × IQR
- Values outside the fences are potential outliers.