Frequency Distribution 5E54F4
1. **Problem Statement:**
We have data on hours spent studying by 40 students: 2, 3, 4, 4, 5, 6, 6, 6, 7, 8, 1, 2, 3, 3, 4, 5, 5, 6, 7, 7, 2, 2, 3, 4, 4, 5, 6, 8, 8, 9, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10.
We will:
a) Construct a frequency distribution table.
b) Add cumulative frequency.
c) Compute mean, median, and mode.
2. **Frequency Distribution Table:**
Count each unique hour value:
| Hours (x) | Frequency (f) |
|-----------|---------------|
| 1 | 2 |
| 2 | 5 |
| 3 | 5 |
| 4 | 6 |
| 5 | 5 |
| 6 | 6 |
| 7 | 4 |
| 8 | 4 |
| 9 | 2 |
| 10 | 1 |
3. **Cumulative Frequency (CF):**
Add frequencies cumulatively:
| Hours (x) | Frequency (f) | Cumulative Frequency (CF) |
|-----------|---------------|---------------------------|
| 1 | 2 | 2 |
| 2 | 5 | 7 |
| 3 | 5 | 12 |
| 4 | 6 | 18 |
| 5 | 5 | 23 |
| 6 | 6 | 29 |
| 7 | 4 | 33 |
| 8 | 4 | 37 |
| 9 | 2 | 39 |
| 10 | 1 | 40 |
4. **Mean Calculation:**
Formula: $$\text{Mean} = \frac{\sum f x}{\sum f}$$
Calculate $$\sum f x$$:
$$2\times1 + 5\times2 + 5\times3 + 6\times4 + 5\times5 + 6\times6 + 4\times7 + 4\times8 + 2\times9 + 1\times10 = 2 + 10 + 15 + 24 + 25 + 36 + 28 + 32 + 18 + 10 = 200$$
Total frequency $$\sum f = 40$$
Mean:
$$\frac{200}{40} = 5$$
5. **Median Calculation:**
Median position: $$\frac{n+1}{2} = \frac{40+1}{2} = 20.5$$th value
From CF, 20.5 lies in the class where CF just exceeds 20.5, which is at hours = 5 (CF=23).
So, median = 5 hours.
6. **Mode Calculation:**
Mode is the value with highest frequency.
Highest frequency is 6, which occurs at hours 4 and 6.
So, the data is bimodal with modes 4 and 6.
**Final answers:**
- Frequency distribution and cumulative frequency as above.
- Mean = 5
- Median = 5
- Mode = 4 and 6 (bimodal)