Question

Determine the precision and accuracy for these data for dioxin.

	Sample 1	Sample 2	Sample 3
Known concentration:	27.9 ng/mL	80.8 ng/mL	281 ng/mL
Experimentally determined values (ng/mL):	39.2	75.2	289
	24.3	61.4	273
	29.6	74.0	251
	26.4	93.3	297
	26.3	72.9	243
	30.5	76.0	269

Sample 1 Precision (Rel Std Deviation) = ?%

Sample 2 Precision (Rel Std Deviation) = ?%

Sample 3 Precision (Rel Std Deviation) = ?%

Sample 1 Accuracy (Relative Error) = ? %

Sample 2 Accuracy (Relative Error) = ? %

Sample 3 Accuracy (Relative Error) = ? %