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AP® Statistics · Unit 1 · Topic 1.5

Graphical Representations for One Quantitative Variable: Topic Checklist (Statistics 1.5)

Specific “I can…” statements for constructing dotplots, stem-and-leaf plots and histograms, each linked to the guide section and practice question that shows whether you can do it.

Work through the list without notes. If you cannot do a statement, follow its link, then come back. Guide = study guide; Practice = practice questions.

Understanding

  • I can explain why graphs of a quantitative variable keep the values in order, unlike a bar chart of categories. (Guide: “Why graph a quantitative variable?”)
  • I can explain the difference between frequency and relative frequency, and why both give a histogram the same shape. (Guide: “Histograms”)
  • I can say which displays keep every individual value and which do not. (Guide: “Choosing a display”; Practice Q7(c))
  • I can explain how changing the bin width can change the appearance of a histogram without either version being wrong. (Guide: “How bin width changes a histogram”; Practice Q3, Q7(a))

Skills

  • I can construct a dotplot on an evenly scaled, labelled axis, stacking repeated values. (Guide: “Dotplots”; Practice Q6)
  • I can construct a stem-and-leaf plot with ordered stems and leaves, empty stems kept, and a key. (Guide: “Stem-and-leaf plots”; Practice Q4)
  • I can split the stems of a crowded stem-and-leaf plot. (Guide: Worked example 1)
  • I can group data into equal-width bins, place boundary values correctly, and make a frequency and relative frequency table. (Guide: Worked example 2; Practice Q5(a))
  • I can draw a frequency or relative frequency histogram with touching bars and labelled axes. (Guide: Worked example 2; Practice Q5(b))
  • I can read counts and proportions from a stem-and-leaf plot, a dotplot or a histogram, using the key or multiplying by n. (Practice Q1, Q2, Q6(c))

Reasoning

  • I can spot a construction error, such as uneven spacing or a boundary value in the wrong bin, and explain its effect. (Practice Q5(c), Q6(b))
  • I can choose a suitable display for a data set and justify the choice. (Guide: “Choosing a display”)
  • I can say when a question cannot be answered from a histogram because a value lies inside a bin. (Guide: Worked example 2; Practice Q7(b))

All ticked? Move on to Topic 1.6, Descriptions for One Quantitative Variable Distributions, or return to the course roadmap.

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