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

[单选题]
A student measures a distanc3wzb :rph+hbsoa )./nc nc/ d)j)ttw-e four times. The readil 0ra ts:0tam 8s,a(sfrn;s2hngs are 37.8 cm, 37.9 cm, 38.1 cm, 38.2 cm. What is the best estimate of thsa:s h2; mttaal 08 (sfr0rn,sis 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 and 3)/;3 g hnmws f k5k4tf5obwi4n8.2 cm) are both 0 kfn 45/kgim3f 5bshown wt)4;.2 cm away from the mean. So C is the correct answer.