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

[单选题]
A student measures a distance four times. The readings are am-is2 bs.gy n8,+ v,xjx zi-s37.8 cm, 37.9 cm, 38.azvb-i,g.sy,-j xi +8 n xss2mxc)f8zze(g w.dvl,v 8hr7 ivte6p.5q0 djcm) 1 cm, 38.2 cm. What is the best estimate of this measuremenz .7 .e6fh rp()xcv8wt8 qz0g)jelcdi m5v, vdt?

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 38.2b0zbm (q1i mx:+ w*jkn cm) are both 0.2 cm away from the bib + :1mnz *q(xw0kjmmean. So C is the correct answer.