- AMean 48; 2 matches
- BMean 40; 4 matches
- CMean 42.5; 3 matches
- DMean 40; 3 matches
Step-by-Step Solution
Total runs =45+30+60+15+50+40=240, so mean =6240=40. She scored more than 40 in matches 1, 3 and 5, i.e. 3 matches (40 itself is not more).
Answer: D) Mean 40; 3 matches
Key idea: Mean of ungrouped data
**Formula**: x̄ = (sum of observations) / (number of observations) = Σx/n.
**Example**: Marks of 5 students: 7, 8, 6, 9, 10.
Sum = 40, n=5. Mean = 40/5 = 8.
**For a frequency distribution**:
x̄ = Σ(fᵢxᵢ) / Σfᵢ
Multiply each value by its frequency, sum, and divide by total frequency.
Example: marks 5, 7, 9 with frequencies 2, 3, 5.
Σfx=5·2 + 7·3 + 9·5 = 10 + 21 + 45 = 76.
Σf=10. Mean = 76 / 10 = 7.6.