Question

a student measures the length of a 1.00 m standard bar. He obtains measurements of 0.80 m, 0.78 m, and 0.79 m. Which describes his measurements? A) both precise and accurate B)accurate but not precise C) neither precise nor accurate D) precise but not accurate

Answer 1

D) precise but not accurate

Answer 2

D) precise but not accurate

Step-by-step explanation:

Although they seem synonymous, accuracy and precision are distinct terms. "Precision" indicates how close the measurements are to each other even if they do not show the same value. To explain further, let's use the example given in the question, where the student measured the length of a bar of 1.0 meters and obtained the measurements 0.80 m, 0.78 m and 0.79 m. Although the student's measurements were not exactly equal to the length of the bar, they were precises because the values came close to the value of each other.

But the fact that the student's measured values are close does not mean that everything is correct. Thus, although all student measurement values come close to each other, they do not correspond to the correct value and this error may yield inaccurate results. That's where accuracy comes in.

"Accuracy" indicates how close to the actual value (the value normally accepted as a reference) is the measured value. In this case, the value of the student's measurements set far from the actual value of the bar length, so we can state that the student's measurements were not accurate.