Mathematics Class 9
Statistics
Weigh averages fairly, stack bars two ways, and pick the chart that answers your question.
11 lessons · ~85 min total
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Lessons in this topic
- 0 Start here A roadmap: the table under a chart, the weighted average, stacked bars, 100% bars, and the honest report. · 4 min You are here
- 1 One table, many questions List each value once with its frequency. Read the mean, median and mode off that table. · 8 min
- 2 The weighted average A weighted average multiplies each mean by its group size, adds, and divides by the sizes added. · 9 min
- 3 What the weights are Multiply each score by its weight, add, divide by the weights added. Multiply every weight by one number above 0. The grade holds. · 8 min
- 4 One bar in parts A stacked bar cuts one bar into segments. The full height of the bar is the total. · 8 min
- 5 Every bar the same height A 100% stacked bar shows shares only. A count needs the total written beside it. · 8 min
- 6 Which chart answers Decide if the question wants a count, a share or a change. Then pick the chart that carries it. · 9 min
- 7 Same numbers, two stories The question picks the chart. Two honest charts of the same data can leave different impressions. · 8 min
- 8 The honest report A report names its question, table, average, chart with total, and units. Each one is chosen. · 9 min
- 9 The big picture Eight ideas, tied back together. · 6 min
- 10 Track quiz Cheat-sheet table plus a reveal quiz — one question per idea. · 8 min
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