…………. Error or ……………. Error is the ratio of …………….. To …………… of the quantity measured.

Answer

To solve the question, we need to fill in the blanks with the appropriate terms related to errors in measurements.

1. **Understanding Error**:
- Error is defined as the difference between the measured value and the true value of a quantity.

2. **Types of Errors**:
- There are different types of errors in measurements, but in this context, we are focusing on two specific types: **Relative Error** and **Fractional Error**.

3. **Filling in the Blanks**:
- The first blank refers to **Relative Error**.
- The second blank refers to **Fractional Error**.
- The third blank refers to **Mean Absolute Error**.
- The fourth blank refers to **Mean Value**.

4. **Final Answer**:
- Therefore, the completed statement is: **Relative Error or Fractional Error is the ratio of Mean Absolute Error to Mean Value of the quantity measured.**

### Step-by-Step Solution:
1. Define what an error is in measurements.
2. Identify the types of errors relevant to the question.
3. Fill in the blanks with the correct terms:
- First blank: Relative Error
- Second blank: Fractional Error
- Third blank: Mean Absolute Error
- Fourth blank: Mean Value
4. Combine the filled terms into a complete statement.