Standard Normal (Z) Curve
The canonical Z-distribution with mean=0 and σ=1, illustrating the three-sigma rule with color-coded bands showing 68%, 95%, and 99.7% coverage.
Draw a standard normal distribution centered at 0. Place vertical markers at every whole standard deviation from -3σ to +3σ. Use progressively lighter blue shading for the ±1σ (68%), ±2σ (95%), and ±3σ (99.7%) bands and label each percentage. Academic publication style, white background.