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

[单选题]
A student measures a di)ug -w+)wx je 7az6xovstanc8vsu2 ktncz;igp1 f s lm3 0sn9/0yj+w1+jzsee four times. The readings are 37.8 cm, 37.9 cm, 38.1 cm, 38.2 cm. What is theg jcv z;/ nss 012 ps3fum+i91+tjyenw8ks0lz 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 .zqs; tk tvr8 i.6v2ar(37.8 cm and 38.2 cm) are both 0.2 cm awaytz.t; rvks6qi av.8 r2 from the mean. So C is the correct answer.