Data Handling
Mean, median, mode, bar graphs, and chance and probability basics.
Chapter Overview
Class 7 data handling covers mean, median, mode, bar graphs with double bars, and chance (probability basics) — interpreting cricket scores, survey data, and weather records.
Mean, Median, Mode
Mean
Sum of observations ÷ Number of observations
Median
Middle value when data is arranged in order
Mode
Most frequently occurring value
Graphs
- Double bar graph compares two data sets
- Choose appropriate scale on y-axis
- Title and labels are mandatory
Chance
Certain event: probability 1. Impossible: probability 0. Equally likely outcomes (fair coin) have equal chances.
Solved Examples
Step-by-step solutions — read each step before checking the final answer.
Example 1: Median
Find median of 12, 7, 15, 9, 11.
- 1Arrange: 7, 9, 11, 12, 15
- 2Middle value (3rd of 5)
Answer
Median = 11
Example 2: Mode
Data: 3, 5, 3, 7, 3, 9. Find mode.
- 13 appears most often (3 times)
Answer
Mode = 3
Key Points to Remember
- ✓ Median for even count: average of two middle values
- ✓ A data set can have more than one mode
- ✓ Mean affected by extreme values
Exam Tips
- • Arrange data in order before finding median
- • Label both axes on graphs
Practice MCQs — Data Handling
Test your understanding with topic-wise multiple choice questions. Explanations appear after each answer.
Mean of 4, 6, 8, 10 is: