Two students independently determine the volume of water delivered by a 10.00-mL pipet. Each student takes 8 measurements, then computes the average volume delivered and the standard deviation. The results are tabulated below.
$$\begin{array} { l l l }
& \text { Average } & \text { St. Dev. } \
\hline
\text { Student A } & 10.4 \mathrm {~mL} & \pm 0.7 \mathrm {~mL} \
\text { Student B } & 10.00 \mathrm {~mL} & \pm 0.02 \mathrm {~mL}
\end{array}$$
Which statement best describes the results?
A) A: good precision, good accuracy. B: good precision, good accuracy.
B) A: good precision, poor accuracy. B: poor precision, good accuracy.
C) A: poor precision, good accuracy. B: good precision, poor accuracy.
D) A: poor precision, poor accuracy. B: good precision, good accuracy.
E) A: poor precision, poor accuracy. B: poor precision, poor accuracy.

Question

Two students independently determine the volume of water delivered by a 10.00-mL pipet. Each student takes 8 measurements, then computes the average volume delivered and the standard deviation. The results are tabulated below. 
$$\begin{array} { l l l } 
& \text { Average } & \text { St. Dev. } \
\hline
\text { Student A } & 10.4 \mathrm {~mL} & \pm 0.7 \mathrm {~mL} \
\text { Student B } & 10.00 \mathrm {~mL} & \pm 0.02 \mathrm {~mL}
\end{array}$$
Which statement best describes the results?
A) A: good precision, good accuracy. B: good precision, good accuracy.
B) A: good precision, poor accuracy. B: poor precision, good accuracy.
C) A: poor precision, good accuracy. B: good precision, poor accuracy.
D) A: poor precision, poor accuracy. B: good precision, good accuracy.
E) A: poor precision, poor accuracy. B: poor precision, poor accuracy.

Quizplus · Accepted Answer

Student A has poor precision due to a high standard deviation and poor accuracy as the average is far from 10.00 mL. Student B has good precision with a low standard deviation and good accuracy as the average is exactly 10.00 mL.

Two Students Independently Determine the Volume of Water Delivered by a 10.00-ML