1. **Problem:** Create a histogram for the ages of 60 people using Sturges' Rule.
2. **Formula:** Sturges' Rule for number of classes $k$ is:
$$k = 1 + \log_2(n)$$
where $n$ is the number of observations.
3. **Calculate number of classes (k):**
$$k = 1 + \log_2(60) \approx 1 + 5.9069 = 6.9069 \approx 7$$
So, $k = 7$ classes.
4. **Determine class width:**
Find the range:
$$\text{Range} = \text{max} - \text{min} = 200 - 18 = 182$$
Class width $w$ is:
$$w = \frac{\text{Range}}{k} = \frac{182}{7} = 26$$
5. **Create class intervals:**
Start from 18, add class width 26 each time:
- 18 - 43
- 44 - 69
- 70 - 95
- 96 - 121
- 122 - 147
- 148 - 173
- 174 - 199
6. **Frequency distribution table:**
Count how many ages fall into each interval:
- 18-43: 7 (18,22,25,30,34,38,42)
- 44-69: 6 (45,50,53,55,60,62,65)
- 70-95: 7 (70,72,75,78,80,82,85,88,90,92,95) actually 11, corrected count
- 96-121: 5 (98,100,105,110,112,115,118,120) actually 8, corrected count
- 122-147: 4 (125,130,132,135,140,145) actually 6, corrected count
- 148-173: 5 (150,152,155,160,165,170) actually 6, corrected count
- 174-199: 5 (175,180,185,190,200) actually 5
Corrected frequencies:
- 18-43: 7
- 44-69: 7
- 70-95: 11
- 96-121: 8
- 122-147: 6
- 148-173: 6
- 174-199: 5
---
7. **Problem 2:** For 100 observations, find $k$ using Sturges' Rule:
$$k = 1 + \log_2(100) \approx 1 + 6.6439 = 7.6439 \approx 8$$
8. **Histogram with class intervals of 10:**
Classes: 1-10, 11-20, 21-30, 31-40, 41-50, 51-60, 61-70, 71-80
9. **Frequency count:**
- 1-10: 9 (1,5,7,10)
- 11-20: 6 (12,14,17,19,20)
- 21-30: 6 (23,25,27,29,30)
- 31-40: 3 (33,35,37)
- 41-50: 4 (40,42,45,47,50)
- 51-60: 3 (53,55,58,60)
- 61-70: 4 (62,65,67,70)
- 71-80: 0
Corrected counts:
- 1-10: 4
- 11-20: 5
- 21-30: 6
- 31-40: 3
- 41-50: 5
- 51-60: 4
- 61-70: 4
- 71-80: 0
---
10. **Problem 3:** Create a bar chart for number of students in departments:
- Mathematics: 120
- Physics: 80
- Chemistry: 100
- Biology: 90
- Computer Science: 110
---
**Final answers:**
- Problem 1: $k=7$, class width $=26$, frequency table as above.
- Problem 2: $k=8$, class intervals of 10, frequency counts as above.
- Problem 3: Bar chart data as above.
Sturges Rule Histogram 1Beefe
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