Author note — to cover (Higher)

Higher only. Draw histograms for grouped continuous data including unequal class widths: calculate every frequency density, choose a sensible density axis, draw touching bars whose areas carry the frequencies. Include one table needing care with class boundaries. Equal-width frequency diagrams for both tiers sit on the earlier page; interpretation is the sibling page. (S3)

• Fluency — direct questions on drawing a histogram, limited to this lesson's stated scope (4 questions).
• Application — use the same skill in unfamiliar or contextual questions without introducing a later method (4 questions).
• Check — questions built around the exclusions and likely misconceptions named in the lesson brief (4 questions).