Kognity IB Physics A.0 Measurements & Uncertainty (id: 87ba97ed9)

[单选题]
A student measures a distancele5d1bk2 9e mkubmp; *m s-k4 v9 t/dxg6z:kfp four times. The readings are 37.8 cm, 37.9 cm, 38.1 cm, 38.2 cm. What is m-/ktvz:4s9gp fdk 6xthe best estimate of this measurement?

A. $37.8 \pm 0.2 \; cm$
B. $37.8 \pm 0.4 \; cm$
C. $38.0 \pm 0.2 \; cm$
D. $38.2 \pm 0.4 \; cm$


参考答案:  C


本题详细解析:
The mean of the measurements is 38.0 cm. The extreme m 55jq39;ghcjgdat:-kzq k7xs (37.8 cm and 38.2 cm) are both 0.2 cm away from t;zm5k 7k hgx95cq3g:jta qj-dhe mean. So C is the correct answer.