The mid value of a class interval is 40. If the class size is 10, then the upper and lower limits of the class are

Options

A. 37.5 and 47.5
B. 45 and 35
C. 37 and 47
D. 47.5 and 37.5

Answer

To find the upper and lower limits of a class interval given the mid value and class size, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Given Values**:
- Mid value (M) = 40
- Class size (X) = 10

2. **Calculate Half of the Class Size**:
- Since the class size is 10, we need to find half of this value.
- Half of class size = \( \frac{X}{2} = \frac{10}{2} = 5 \)

3. **Determine the Lower Limit**:
- The lower limit (AI) can be calculated by subtracting half of the class size from the mid value.
- Lower limit (AI) = Mid value - Half of class size
- \( AI = 40 - 5 = 35 \)

4. **Determine the Upper Limit**:
- The upper limit (BI) can be calculated by adding half of the class size to the mid value.
- Upper limit (BI) = Mid value + Half of class size
- \( BI = 40 + 5 = 45 \)

5. **Final Result**:
- Lower limit = 35
- Upper limit = 45

### Conclusion:
The lower limit of the class interval is 35 and the upper limit is 45.

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