Question

A sample of a rare metal weighs 18.15 g. Several labs weigh the sample repeatedly. Which lab has the most precise measurements? A. Lab 1: 17.99 g, 18.15 g, 18.23 g B. Lab 2: 18.1 g, 18.3 g, 18.2 g C. Lab 3: 18.11 g, 18.13 g, 18.97 g D. Lab 4: 18.93 g, 19.03 g; 18.95 g

Answer 1

D. Lab 4

Step-by-step explanation:

Measurements in scientific experiments require the collection of data. The precision of a measurement refers to how close a measurement value is to one another.

N.B: The accuracy of a measurement is different from the precision. Accuracy is how close the measured values are to the true value.

To calculate the precision of measured values in different labs for a weighed metal, we use the range of values i.e. the difference between the highest value and lowest value for each lab.

Lab 1: 17.99 g, 18.15 g, 18.23 g

Range= 18.23 - 17.99 = 0.24

Precision result (mean±range)= 18.12±0.24

Lab 2: 18.1 g, 18.2 g, 18.3 g

Range= 18.3 - 18.1 = 0.2

Precision result: 18.2±0.2

Lab 3: 18.11 g, 18.13 g, 18.97 g

Range= 18.97 - 18.11 = 0.86

Precision result: 18.40±0.86

Lab 4: 18.93 g, 18.95 g, 19.03 g

Range= 19.03 - 18.93 = 0.1

Precision result: 18.97±0.1

Based on the range of values in the precision results from each lab, it is evident that Lab 4 has the most precise measurements because the repeated values didn't vary much from one another compared to values from other labs.