The class marks of a frequency distribution are 104, 114, 124, 134, 144, 154, 164. Find the class size

Options

A. 10
B. 5
C. 15
D. 19

Answer

To find the class size from the given class marks of a frequency distribution, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Class Marks**:
The class marks given are: 104, 114, 124, 134, 144, 154, 164.

2. **Select Two Consecutive Class Marks**:
We can choose any two consecutive class marks to find the class size. Let's take the first two class marks: 104 and 114.

3. **Calculate the Difference**:
To find the class size, we subtract the smaller class mark from the larger class mark:
\[ \text{Class Size} = 114 - 104 = 10 \]

4. **Verify with Other Class Marks**:
To ensure consistency, we can check the difference between other consecutive class marks:
- Between 114 and 124:
\[ 124 - 114 = 10 \]
- Between 124 and 134:
\[ 134 - 124 = 10 \]
- Between 134 and 144:
\[ 144 - 134 = 10 \]
- Between 144 and 154:
\[ 154 - 144 = 10 \]
- Between 154 and 164:
\[ 164 - 154 = 10 \]

5. **Conclusion**:
Since the difference between all pairs of consecutive class marks is consistently 10, we conclude that the class size is:
\[ \text{Class Size} = 10 \]

### Final Answer:
The class size is **10**.