NCERT Exemplar Solutions
Class 10 - Mathematics - CHAPTER 13: Statistics and Probability - Exercise 13.3

Question 11

Step 1: Look at the given table. It is in “more than or equal to” form. This means: for each mark limit, the number tells us how many students scored at least those marks.

Step 2: To convert into a normal frequency table (0–10, 10–20, etc.), we must subtract successive values.

Step 3: Calculate frequencies one by one.

• For 0–10: Total candidates (≥0) – candidates (≥10) = 34 – 32 = 2
• For 10–20: Candidates (≥10) – candidates (≥20) = 32 – 30 = 2
• For 20–30: Candidates (≥20) – candidates (≥30) = 30 – 27 = 3
• For 30–40: Candidates (≥30) – candidates (≥40) = 27 – 23 = 4
• For 40–50: Candidates (≥40) – candidates (≥50) = 23 – 17 = 6
• For 50–60: Candidates (≥50) – candidates (≥60) = 17 – 11 = 6
• For 60–70: Candidates (≥60) – candidates (≥70) = 11 – 6 = 5
• For 70–80: Candidates (≥70) – candidates (≥80) = 6 – 4 = 2
• For 80–90: Candidates (≥80) – candidates (≥90). Since ≥90 is not given, we assume it is 0. So, 4 – 0 = 4

Step 4: Write all these frequencies in the table beside their class intervals.

Final Note: Always remember: when data is given in “more than or equal to” form, you can find the actual frequency by subtracting successive entries.