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

[单选题]
A student measures at ,d 81-vsj5v/rtd+z8b rrrfo -,c,a mhki z4v6 t,dxcdistance four times. The readings are 37.8 cm, 37.9 cm, 38.1 cm, 38.2 cm. What is the best et4i,ha k mz6xcc vd,,-stimate 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 extremes (37.8 +hq/ om ,:krdexh+v6argro-)1 lnv2 ycm and 38.2 cm) are both 0.2 cm away from the mean. So C is the corrh6r)n 2k -/h+g ,1dvvx :o+qlomyear rect answer.