Mode Mean
1. **Problem Statement:** Given the age distribution of patients admitted to a hospital and their frequencies, find the mode and mean and then compare these measures of central tendency.
2. **Data Table:**
Age intervals: 5-15, 15-25, 25-35, 35-45, 45-55, 55-65
Number of patients (frequency): 6, 11, 21, 23, 14, 5
3. **Find the Mode:** The mode is the class interval with the highest frequency. Here, max frequency = 23 in the interval 35-45. So, mode class is 35-45.
4. **Calculate Mean:**
Step 1: Find midpoints (x) of each class:
- 5 - 15: $\frac{5+15}{2}=10$
- 15 - 25: $\frac{15+25}{2}=20$
- 25 - 35: $\frac{25+35}{2}=30$
- 35 - 45: $\frac{35+45}{2}=40$
- 45 - 55: $\frac{45+55}{2}=50$
- 55 - 65: $\frac{55+65}{2}=60$
Step 2: Multiply midpoints by frequencies to find $f \times x$:
- $6 \times 10 = 60$
- $11 \times 20 = 220$
- $21 \times 30 = 630$
- $23 \times 40 = 920$
- $14 \times 50 = 700$
- $5 \times 60 = 300$
Step 3: Find sum of frequencies, $\sum f = 6+11+21+23+14+5=80$
Step 4: Find sum of $f \times x$, $\sum fx = 60+220+630+920+700+300=2830$
Step 5: Calculate mean
$$\text{Mean} = \frac{\sum fx}{\sum f} = \frac{2830}{80} = 35.375$$
5. **Interpretation and Comparison:**
- The mode class is 35-45 years, meaning most patients fall within this age group.
- The mean age is approximately 35.38 years, which also lies in the 35-45 interval.
- Since the mean and mode are close, the age distribution is roughly symmetric or moderately skewed.
- Mode gives the most frequent age group, while mean gives the average age of patients.
**Final answers:**
- Mode class: 35-45 years
- Mean age: 35.375 years