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

[单选题]
A student measures a d2+ c yhn,v /5kgij1 tb8r tq:zgo6q 6om:gywf,istance four times. The readings acl u3jl1d5)fg1gj 7f are 37.8 cm, 37.9 cm, 38.1 cm, 38.2 cm. What is the best estimate of tu 7ajf1 l5f1gd)3jclghis 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 cm an;zy- c: fhxf,td 38.2 cm) are bc,f:tfy;z-h x oth 0.2 cm away from the mean. So C is the correct answer.