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

[单选题]
A student measures a yx36*fedf-z je21yc r dists9 8cu -vhm .eete1-ikt qif) nb2v3-tance four times. The readings are 37.8 cm, 37.9 cm, 38.1 cvsh ee t 2tke8mf)- 39i.1vtc q-in-bum, 38.2 cm. What is the 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 extremes (37.8 cm and 38.2 cm) yl h qn v z1iqit+qaqia 2,6g4h*5u6j*are both 0.2 cm away from the mean. So C is the correct answer nv gl+ qi5y26hi*qhaq6ztu4iq *1 ,aj.