The class mark of 10–15 (exclusive form) is_______

Answer

To find the class mark of the interval 10–15 (exclusive form), we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Lower and Upper Limits**:
The lower limit of the class interval is 10, and the upper limit is 15.

2. **Use the Formula for Class Mark**:
The class mark (or midpoint) is calculated using the formula:
\[ \text{Class Mark} = \frac{\text{Lower Limit} + \text{Upper Limit}}{2} \]

3. **Substitute the Values**:
Substitute the lower limit (10) and upper limit (15) into the formula:
\[ \text{Class Mark} = \frac{10 + 15}{2} \]

4. **Calculate the Sum**:
First, calculate the sum of the lower and upper limits:
\[ 10 + 15 = 25 \]

5. **Divide by 2**:
Now, divide the sum by 2 to find the class mark:
\[ \text{Class Mark} = \frac{25}{2} = 12.5 \]

6. **Final Answer**:
Therefore, the class mark of the interval 10–15 (exclusive form) is **12.5**.