Question

a measurement was taken three times. the correct measurement was 68.1 ml. circle whether the set of measurements is accurate, precise, both, or neither.
a) 78.1 ml, 43.9 ml, 2 ml accurate precise both neither
b) 68.1 ml, 68.2 ml, 68.0 ml accurate precise both neither
c) 98.0 ml, 98.2 ml, 97.9 ml accurate precise both neither
d) 72.0 ml, 60.3 ml, 68.1 ml accurate precise both neither

Explanation:

• Accuracy refers to how close a measurement is to the true value.
• Precision refers to how close multiple measurements are to each other.

Part a)

The values \(78.1\space mL\), \(43.9\space mL\), \(2\space mL\) are not close to the true value \(68.1\space mL\) (not accurate) and are not close to each other (not precise).

Part b)

The values \(68.1\space mL\), \(68.2\space mL\), \(68.0\space mL\) are close to the true value \(68.1\space mL\) (accurate) and are close to each other (precise).

Part c)

The values \(98.0\space mL\), \(98.2\space mL\), \(97.9\space mL\) are close to each other (precise) but not close to the true value \(68.1\space mL\) (not accurate).

Part d)

The values \(72.0\space mL\), \(60.3\space mL\), \(68.1\space mL\) are not close to each other (not precise) and \(72.0\space mL\) and \(60.3\space mL\) are not close to the true value \(68.1\space mL\) (not accurate).

Answer:

a) neither
b) both
c) precise
d) neither