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

[单选题]
A student measures a distance four ti)xv.y4c -z vp*) qckyisfhpx;:g*v-cvu w: *j, viy: 9uwqw8imes. The readings are 37.8 cm, 37.9 cm, 38.1 cm, 38.2 cm. What is the best estimate of this measuremej 8cvu wq vi::*;y fxvh-w,:9s*wpiugnt?

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 aw9 kq(wy9ck .lnd 38.2 cm) are both 0.2 c9lq(kcwyw .k9 m away from the mean. So C is the correct answer.