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

[单选题]
A student measures a dist6vuu*z7 -vmh 9t9uvreance four 2 rs:9+x bjlrztimes. The readings are 37.8 cm, 37.9 cm, 38.1 cm, 38.2 cm. What is tl 92rrzxb+j :she 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 extsed )*o p*uah:remes (37.8 cm and 38.2 cm) are both 0.2 cm away from the mean. So C ihus * p:)*adoes the correct answer.