Key features to describe:

• Shape: Symmetric, skewed left, skewed right, bimodal, uniform
• Center: Where the "middle" of the data falls
• Spread: Range from minimum to maximum
• Outliers: Unusual values

Dotplots

Each data point is represented by a dot above a number line. Best for small datasets.

Stemplots (Stem-and-Leaf Plots)

Each data value is split into a stem (leading digits) and leaf (trailing digit).

Example: For the data 23, 25, 31, 34, 37: $\text{Stem} | \text{Leaf}$ $2 | 3 \; 5$ $3 | 1 \; 4 \; 7$

Back-to-back stemplots compare two distributions.

Describing Shape

• Symmetric: Left and right sides are approximately mirror images
• Skewed right: Tail extends to the right (mean > median)
• Skewed left: Tail extends to the left (mean < median)
• Bimodal: Two peaks
• Uniform: Approximately equal frequencies

AP Tip: Always describe distributions using Shape, Outliers, Center, and Spread (SOCS).