---
source: ncert
topic: statistics
class_level: class_6
chapter: ch9
difficulty: beginner
---

Class 6 | Ch9: Data Handling
Mean = Sum/Count. Median = middle value when arranged in order.
Odd count: middle term. Even count: average of two middle terms.
Mode = most frequent value. Range = Max - Min.
Bar graph: equal width bars, height=frequency. Tally: groups of 5.
Probability: P(event)=favourable/total. Always between 0 and 1.
Example: 12,15,11,18,15,13,20,15,10. Mean=129/9=14.33. Arranged→Median=15. Mode=15.
P(even on die)=3/6=1/2.
Must arrange data BEFORE finding median. Mode is most FREQUENT not largest.