NCERT Solutions for Class 7th Maths Chapter 5 Connecting the Dots...
Updated on 2026-09-19
About this chapter
A statistical question is one you answer by collecting data, because the answer varies. A statistical statement is a claim about that data, given as a number, a proportion or a prediction. Arithmetic Mean = (sum of all the values) ÷ (number of values). It is the fair share — the value everyone would get if the total were shared equally. Median = the middle value of the sorted data. With an even number of values, take the average of the two middle ones. Half the data lies at or above it. An outlier is a value far away from the rest. It drags the mean towards itself but barely moves the median. Outlier low ⇒ mean median. A dot plot stacks one dot per value on a number line. It shows the minimum, the maximum, the range and where the data clusters — but it loses the original order of the value
- Of Questions and Statements
- Representative Values
- Average as Fair-Share
- Know Your Onions!
- Dot Plots
- Outliers and Medians
- Are you a bookworm?
- Are We on the Same Page?
- Measures of Central Tendency
- Of Ends and the Essence
Quick revision
| Idea | What it is | Why it matters | Example |
|---|---|---|---|
| Statistical question | A question answered by collecting data | The answer varies, so one value will not do | How old are the dogs on this street? |
| Not a statistical question | A question with one fixed answer | Nothing varies, so no data is needed | Do you like reading? |
| Mean (Average) | Sum of values ÷ number of values | Balances the highs and the lows into one fair share | (2+7+9+4+3) ÷ 5 = 5 |
| Median | Middle value of the sorted data | Half the values are at or above it | 118, 165, 170, 173, 175 → 170 |
| Median, even count | Average of the two middle values | There is no single middle number | (164 + 165) ÷ 2 = 164.5 |
| Outlier | A value far from the rest of the data | It shifts the mean a lot, the median very little | 118 cm among 165–175 cm |
| Mean < median | Data has a low outlier or a low tail | The mean is pulled down | Poovizhi's family: 160.2 < 170 |
| Mean > median | Data has a high outlier or a high tail | The mean is pulled up | Short stories: 8.13 > 6 |
| Range | Maximum − minimum | Measures how spread out the data is | Wahapur onions: 60 − 17 = 43 |
| Zero vs no value | A score of 0 counts; a match not played does not | Dividing by the wrong count gives a wrong mean | (57+13+0+84+51+27) ÷ 6 |
| Dot plot | One dot per value stacked on a number line | Shows clusters, gaps, ends and repeats | Onion prices 10 – 60 |
| Clustered bar graph | Two or three bars side by side per category | Compares groups across categories or years | Yahapur vs Wahapur, month by month |
| Reading a graph | Step 1 identify, Step 2 infer | Stops us claiming more than the data shows | Scale: 1 unit = 20 rockets |
Exercises
- In-text Questions — Of Questions and Statements Page 98
- Math Talk — Representative Values Page 98 – 99
- Average as Fair-Share — In-text Questions Page 100
- Figure it Out — Representative Values Page 101
- Know Your Onions! — Math Talk Page 101 – 102
- Dot Plots — In-text Questions Page 103
- Know Your Onions! — Math Talk Page 104
- Outliers and Medians — Math Talk Page 105 – 106
- Are you a bookworm? — In-text Questions Page 107 – 108
- Are We on the Same Page? — In-text Questions Page 108
- Measures of Central Tendency — Math Talk Page 108 – 109
- Of Ends and the Essence — In-text Questions Page 109 – 110
- How long is a minute? — Math Talk Page 110
- Zero Median Runs Scored! / Zero vs No value — In-text Questions Page 111
- Figure it Out — Representative Values Page 112 – 113
- In-text Questions — Visualising Data Page 114 – 115
- …9…8…7…6…5…4…3…2…1…Take Off! — In-text Questions Page 116 – 11810
- Summer and Winter at the Same Time — Math Talk Page 118 – 121
- All it Takes is a Minute — In-text Questions Page 122
- Figure it Out — Visualising Data Page 122 – 125
- Math Talk — Data Detective Page 125 – 126
- Telling Tall Tales — Math Talk Page 127 – 128
- Figure it Out — Data Detective Page 129 – 133
- Puzzle Time