The mean length of an object is 5 cm. Which of the following measurements is most accurate?

Options

A. `4.9 cm`
B. `4.805 cm`
C. `5.25 cm`
D. `5.4 cm`

Explanation

To determine which measurement is the most accurate among the given options, we will calculate the absolute error for each measurement compared to the mean length of 5 cm. The measurement with the least absolute error will be considered the most accurate.

### Step-by-Step Solution:

1. **Identify the Mean Length**:
The mean length of the object is given as 5 cm.

2. **List the Measurements**:
Let's assume the measurements provided are:
- Option A: 4.9 cm
- Option B: 4.805 cm
- Option C: 5.25 cm
- Option D: 5.4 cm

3. **Calculate Absolute Errors**:
- For Option A:
\[ \text{Error}_A = |5 - 4.9| = 0.1 \text{ cm} \]
- For Option B:
\[ \text{Error}_B = |5 - 4.805| = 0.195 \text{ cm} \]
- For Option C:
\[ \text{Error}_C = |5 - 5.25| = 0.25 \text{ cm} \]
- For Option D:
\[ \text{Error}_D = |5 - 5.4| = 0.4 \text{ cm} \]

4. **Compare the Absolute Errors**:
- The calculated errors are:
- Error for A: 0.1 cm
- Error for B: 0.195 cm
- Error for C: 0.25 cm
- Error for D: 0.4 cm

5. **Determine the Most Accurate Measurement**:
- The measurement with the least absolute error is Option A, which has an error of 0.1 cm.

6. **Conclusion**:
- Therefore, the most accurate measurement is **Option A** (4.9 cm).