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

[单选题]
A student measures a distance four times. The readings ar(yydd)x -k,7 i m/1 vu;ttnajue 37.8 cm,*)z ls:yq- gku 37.9 cm, 38.1 cm, 38.2 cm. Wha:g-l* ) skqyzut 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 38wt/p jeg ,nb1bzqk5 +6.0 cm. The extremes (37.8 cm and 38.2 cm) are both 0.2t/,5kbqz 6g+ 1ebw pjn cm away from the mean. So C is the correct answer.