Presentation of Data
Class 11 · Economics
4 ideas in Class 11 Economics, explained in plain words, with games and quizzes to practise.
Tabulation Rules
Part of: Tables and Bars
Table numbers identify; titles summarise; stubs row-label; captions head columns; footnotes source exceptions; compact rows aid reading.
Why it matters. Tables compress data. Labels prevent misread.
Key words
- Table number
- : The serial that identifies a table for easy reference.
- Title
- : The short line above a table summarising what it shows.
- Stub
- : The left column of a table carrying the row labels.
- Caption
- : The heading of a table column describing its entries.
- Footnote
- : A note below a table sourcing data or explaining exceptions.
Try it in two minutes
- Number and title.
- Label rows, columns.
- Footnote sources.
Try at home. Table monthly expenses.
Bar and Pie Diagrams
Part of: Tables and Bars
Simple bars compare single series; multiple bars group years; subdivided bars stack parts; pies angle shares of totals.
Why it matters. Pictures persuade fast. Parts show composition.
Formulas
- Pie angle = percentage of component x 3.6
- Full circle = 100 percent = 360 degrees
Key words
- Simple bar
- : Single bars comparing one series, with length showing size.
- Multiple bars
- : Grouped bars comparing several series across years.
- Subdivided bar
- : Stacked bars splitting each total into its parts.
- Pie diagram
- : A circle split into shares of a total, drawn from percentages.
Try it in two minutes
- Scale bars evenly.
- Group or stack series.
- Angle the shares.
Try at home. Bar-chart weekly spending.
Histogram and Polygon
Part of: Histograms and Ogives
Histograms join bars edge to edge; area shows frequency; polygons join midpoints; smoothed curves trace trends.
Why it matters. Shapes reveal skew. Areas compare classes.
Formulas
- Frequency density = frequency / class width
- Equal classes: bar height = frequency
Key words
- Histogram
- : Joined edge-to-edge bars for continuous data, where area shows frequency.
- Frequency polygon
- : A line joining class midpoints that traces the shape of a distribution.
- Frequency density
- : Frequency divided by class width, used as bar height for unequal classes.
- Continuous classes
- : Intervals whose edges meet, so histogram bars touch without gaps.
Try it in two minutes
- Join bars edgeless.
- Mark midpoints.
- Join the dots.
Try at home. Histogram class marks.
Cumulative Curves
Part of: Histograms and Ogives
Less-than cumulates upward; more-than cumulates downward; crossings mark medians; rising slopes never fall.
Why it matters. Ogives locate medians fast. Crossings verify counts.
Formulas
- Median = value where less-than and more-than ogives meet
Key words
- Less-than ogive
- : A rising cumulative curve adding frequencies upward from the start.
- More-than ogive
- : A falling cumulative curve cumulating frequencies downward from the end.
- Median point
- : The value where the two ogives cross, splitting the data in half.
- Cumulative frequency
- : The running total of frequencies up to each class edge.
Try it in two minutes
- Cumulate frequencies.
- Plot upper limits.
- Cross to find median.
Try at home. Ogive family ages.
What your child will practise
- Bar and Pie Diagrams: Ocean Puzzle (Clue Puzzle)
- Bar and Pie Diagrams: Ocean Quick Fire (Quick Fire)
- Cumulative Curves: Jungle Puzzle (Clue Puzzle)
- Histogram and Polygon: Space Quest (Flip and Match)
- Tabulation Rules: Desert Quick Fire (Quick Fire)
- Quiz: Bar and Pie Diagrams (8 questions)
- Quiz: Cumulative Curves (8 questions)
- Quiz: Histogram and Polygon (8 questions)
- Quiz: Tabulation Rules (8 questions)