Organisation of Data
Class 11 · Economics
4 ideas in Class 11 Economics, explained in plain words, with games and quizzes to practise.
Ways to Classify
Part of: Classification Basics
Chronological sorts years; spatial sorts regions; qualitative sorts traits; quantitative sorts measures; good classes stay exclusive and exhaustive.
Why it matters. Sorting reveals patterns. Clean classes prevent overlap.
Formulas
- Good classes are exclusive and exhaustive: no overlap, no gaps
Key words
- Chronological classification
- : Sorting data by years or periods.
- Spatial classification
- : Sorting data by states, districts or regions.
- Qualitative classification
- : Sorting by qualities like gender or occupation.
- Quantitative classification
- : Sorting by measurable quantities like marks or income.
- Mutually exclusive
- : Classes that share no observation with each other.
- Exhaustive
- : Classes that together cover every observation.
Try it in two minutes
- Pick the basis.
- Exclude overlaps.
- Cover everything.
Try at home. Sort coins by year.
Variables and Frequencies
Part of: Classification Basics
Discrete jumps whole steps; continuous flows smoothly; frequency counts repeats; arrays pair values with counts; tallies group five bars.
Why it matters. Types shape tables. Tallies speed counting.
Formulas
- Frequencies add up to the total number of observations
Key words
- Discrete variable
- : A quantity that jumps in whole steps, like family size.
- Continuous variable
- : A quantity that flows smoothly, like height.
- Frequency
- : How many times a value occurs in the data.
- Frequency array
- : Values paired with their counts in a table.
- Tally mark
- : Bundled bars counting five observations at a time.
Try it in two minutes
- Spot jumps or flow.
- Count repeats.
- Bar every fifth.
Try at home. Tally family sizes.
Exclusive and Inclusive Classes
Part of: Class Intervals
Exclusive drops upper into next; inclusive keeps both but needs gaps; true boundaries halve the gap; midpoints anchor averages; width spans upper-minus-lower.
Why it matters. Limits place every value. Midpoints feed means.
Formulas
- Class mark = (upper limit + lower limit) / 2
- True upper limit = stated upper + gap / 2
- Width = upper limit - lower limit
Key words
- Exclusive class
- : Classes that drop the upper value into the next class.
- Inclusive class
- : Classes that keep both ends, needing gap correction.
- Class boundary
- : The exact edge after sharing the gap with the neighbour.
- Class mark
- : The midpoint of a class, used for averages.
- Class width
- : The span of a class from lower to upper limit.
Try it in two minutes
- Read both limits.
- Fix gaps to boundaries.
- Midpoint each class.
Try at home. Group heights in tens.
Frequency Tables
Part of: Class Intervals
Ranges split into equal widths; counts cumulate upward; relative shares divide by totals; loss of detail trades for readability.
Why it matters. Tables compress thousands. Cumulation aids medians.
Formulas
- Relative frequency = class frequency / total frequency
- Cumulative frequency adds each class count to all above it
Key words
- Frequency table
- : Data grouped into classes with counts, in a table.
- Cumulative frequency
- : Running total of counts up to each class.
- Relative frequency
- : A class share of the total, between 0 and 1.
- Continuous series
- : Grouped data shown as unbroken class ranges.
Try it in two minutes
- Split the range.
- Count per class.
- Cumulate upward.
Try at home. Table class weights.
What your child will practise
- Exclusive and Inclusive Classes: Jungle Puzzle (Clue Puzzle)
- Exclusive and Inclusive Classes: Jungle Quick Fire (Quick Fire)
- Frequency Tables: Candy Puzzle (Clue Puzzle)
- Variables and Frequencies: Ocean Quest (Flip and Match)
- Ways to Classify: Space Quick Fire (Quick Fire)
- Quiz: Exclusive and Inclusive Classes (8 questions)
- Quiz: Frequency Tables (8 questions)
- Quiz: Variables and Frequencies (8 questions)
- Quiz: Ways to Classify (8 questions)