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

[单选题]
A student measures a distance four times.qqkoytu9sp8 a+ vjttwj,/ 2r b xz3q7o) o*0u3 The readings ann;(4 gc8i mg1ph* nbrre 37.8 cm, 37.9 cm, 38.1 cm, 38.2 cm. What i*gp cbri h4m8n( 1n;gns 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 ex6d1x8(n 8ice 2c urde,vl ix6stremes (37.8 cm and 38.2 cm) are both 0.2 cm away from the mean. So C xl8v d,i (i8sc6dx261nure ec is the correct answer.