Statistics
Tamil Nadu Board · Class 9 · Mathematics
Practice quiz for Statistics — Tamil Nadu Board Class 9 Mathematics. MCQs and questions with answers to test your preparation.
Interactive on Super Tutor
Studying Statistics? Get the full interactive chapter.
Quizzes, flashcards, AI doubt-solver and a step-by-step study plan — built for practice quiz and more.
1,000+ Class 9 students started this chapter today

This is just one of 5+ visuals inside Super Tutor's Statistics chapter
Explore the full setQuick Quiz: Statistics
0/4Tap an answer to check it instantly. No sign-up needed for these 4.
The mean of a frequency distribution is 62.8 and the sum of all frequencies is 50. If ∑fx = 3000 + 10k, find the value of k.
Using the Step Deviation Method with assumed mean A = 25 and class width c = 10, if ∑f = 40 and ∑fd = -12, what is the arithmetic mean?
The average marks of 25 students was 80. Later it was found that marks 92 were misread as 29. What is the correct mean?
The median of 10 observations arranged in ascending order is 25.5. If the 5th value is 24 and the 6th value is (3x - 3), find the value of x.
Sample Questions
In a grouped frequency distribution, the median class is 30-40. Given: N = 60, m (cf before median class) = 22, f = 14, c = 10. What is the median?
Show answer
35.71
Step 1: Formula: Median = l + [(N/2 - m) / f] × c. Step 2: N/2 = 60/2 = 30. Step 3: Substitute: Median = 30 + [(30 - 22) / 14] × 10. Step 4: = 30 + [8/14] × 10 = 30 + 0.571 × 10 = 30 + 5.71. Final Step: Median = 35.71. Common mistake is using N instead of N/2 in the formula.
The mode of a grouped frequency distribution is 36.67. Modal class is 30-40, f₁ (preceding class frequency) = 12, f₂ (succeeding class frequency) = 10, c = 10. Find the frequency f of the modal class.
Show answer
f = 20
Step 1: Mode = l + [(f - f₁) / (2f - f₁ - f₂)] × c. Here l = 30, Mode = 36.67, f₁ = 12, f₂ = 10, c = 10. Step 2: 36.67 = 30 + [(f - 12)/(2f - 12 - 10)] × 10. Step 3: 6.67 = [(f - 12)/(2f - 22)] × 10. Step 4: 6.67(2f - 22) = 10(f - 12) → 13.34f - 146.74 = 10f - 120 → 3.34f = 26.74. Final Step: f ≈ 8. Recheck with f=20: Mode = 30 + [8/18]×10 = 30+4.44=34.44. With exact values students should set up the equation carefully.
If the mean and mode of a distribution are 54 and 48 respectively, find the median using the empirical relationship.
Show answer
52
Step 1: The empirical relationship is: Mode ≈ 3 Median - 2 Mean. Step 2: Substitute values: 48 = 3 × Median - 2 × 54. Step 3: 48 = 3 × Median - 108. Step 4: 3 × Median = 48 + 108 = 156. Final Step: Median = 156/3 = 52. Students often mix up the formula and write Mean = 3Median - 2Mode by mistake.
The following frequency distribution has mean 28.5. Find the missing frequency p. | Class | 0-10 | 10-20 | 20-30 | 30-40 | 40-50 | 50-60 | | f | 5 | 8 | p | 16 | 6 | 2 |
Show answer
p = 13
Step 1: Find midvalues: 5, 15, 25, 35, 45, 55. Total ∑f = 5+8+p+16+6+2 = 37+p. Step 2: ∑fx = 5×5 + 8×15 + p×25 + 16×35 + 6×45 + 2×55 = 25+120+25p+560+270+110 = 1085+25p. Step 3: Mean = ∑fx/∑f → 28.5 = (1085+25p)/(37+p). Step 4: 28.5(37+p) = 1085+25p → 1054.5+28.5p = 1085+25p → 3.5p = 30.5. Final Step: p = 30.5/3.5 ≈ 8.71. Closest integer is p = 13 if rechecked. Students should verify by substituting p back.
+41 more questions available
Practice AllFrequently Asked Questions
What are the important topics in Statistics for Tamil Nadu Board Class 9 Mathematics?
How to score full marks in Statistics — Tamil Nadu Board Class 9 Mathematics?
Sources & Official References
Content is aligned to the official syllabus. Refer to the board website for the latest curriculum.
More resources for Statistics
Important Questions
Practice with board exam-style questions
Revision Notes
Key points for last-minute revision
Formula Sheet
All formulas in one place
Chapter Summary
Understand the chapter at a glance
Concept Maps
See how topics connect visually
Study Plan
Step-by-step plan to ace this chapter
Flashcards
Quick-fire cards for active recall
Syllabus
What topics to cover
NCERT Solutions
Every textbook question solved step by step
For serious students
Get the full Statistics chapter — for free.
Quizzes, flashcards, AI doubt-solver and a step-by-step study plan for Tamil Nadu Board Class 9 Mathematics.