Chapter 13: Statistics

Questions

1. Median: $l = 20, cf = 8, f = 10, h = 10, n = 50$.
2. Mean $= 30$, Median $= 32$; find mode.
3. Median of $12, 15, 18, 22, 24, 25, 28$.
4. Intervals for class marks $15, 25, 35$ (size $10$).
5. Mean of $10, 20, 30, 40$ with freq $2, 3, 4, 1$.
6. Modal class from freq $5, 12, 20, 15, 8$ (classes size $10$, start $20$).
7. $n$ observations sum to $210$; mean $10.5$. Find $n$.
8. Find the median of first $9$ odd natural numbers.
9. For classes $0-10, 10-20, 20-30, 30-40, 40-50$ with freq $5, 8, 15, 10, 7$: find mean.
10. Modal age from data $10, 12, 15, 12, 18, 12, 20$.

Extra Practice (Optional)

• Draw an ogive for a given frequency table.
• Cumulative frequency of $2, 3, 5, 10, 7, 3$.
• Verify empirical relation for given data.
• Mode formula parts labelled correctly.
• Median class of a distribution.