Student Scores Fec5B7
1. **Problem Statement:** We have scores of 50 students and need to find the mean, median, mode, first quartile (Q1), fourth decile (D4), 60th percentile (P60), and range.
2. **Step 1: Organize the data**
Sort the scores in ascending order:
$$34, 37, 39, 42, 44, 46, 49, 49, 50, 50, 52, 53, 54, 56, 57, 58, 59, 60, 60, 61, 64, 64, 65, 65, 66, 68, 68, 68, 70, 71, 71, 71, 73, 74, 74, 75, 75, 75, 76, 77, 77, 77, 78, 78, 84, 85, 87, 88, 90, 90, 95$$
3. **Step 2: Calculate the Mean**
Mean formula: $$\text{Mean} = \frac{\sum \text{scores}}{n}$$
Sum of scores = 53+75+52+...+60 = 3333
Number of scores $n=50$
$$\text{Mean} = \frac{3333}{50} = 66.66$$
4. **Step 3: Calculate the Median**
Median is the middle value. For even $n$, median is average of $\frac{n}{2}$th and $\left(\frac{n}{2}+1\right)$th values.
Positions: 25th and 26th scores
25th score = 66, 26th score = 68
$$\text{Median} = \frac{66 + 68}{2} = 67$$
5. **Step 4: Calculate the Mode**
Mode is the most frequent score.
Frequencies: 75 appears 3 times, 71 appears 3 times, 77 appears 3 times, 68 appears 3 times
Modes = 68, 71, 75, 77 (multimodal)
6. **Step 5: Calculate Q1 (First Quartile)**
Q1 is the 25th percentile.
Position: $\frac{25}{100} \times (50+1) = 12.75$th score
Interpolate between 12th (54) and 13th (56) scores:
$$Q1 = 54 + 0.75 \times (56 - 54) = 54 + 1.5 = 55.5$$
7. **Step 6: Calculate D4 (Fourth Decile)**
D4 is the 40th percentile.
Position: $\frac{40}{100} \times (50+1) = 20.4$th score
Interpolate between 20th (61) and 21st (64) scores:
$$D4 = 61 + 0.4 \times (64 - 61) = 61 + 1.2 = 62.2$$
8. **Step 7: Calculate P60 (60th Percentile)**
Position: $\frac{60}{100} \times (50+1) = 30.6$th score
Interpolate between 30th (71) and 31st (71) scores:
$$P60 = 71 + 0.6 \times (71 - 71) = 71$$
9. **Step 8: Calculate Range**
Range = Maximum score - Minimum score
$$\text{Range} = 95 - 34 = 61$$
**Final answers:**
- Mean = 66.66
- Median = 67
- Mode = 68, 71, 75, 77
- Q1 = 55.5
- D4 = 62.2
- P60 = 71
- Range = 61