Answer the following question and explain

Part 5E Error and uncertainty

Expressing error and uncertainty is a basic requirement in laboratory work. In this part of the, assessment you will be determining the errors and uncertainties associated with repeated measurements of standard materials. Use the data set below to calculate the required values.

Measurand	Reading 1	Reading 2	Reading 3	Reading 4	True value
Conductivity	6.64	6.59	6.68	6.67	6.67 mS.cm-1
Nitrate	3.9	3.8	3.9	3.9	4.0 mg/L
E.Coli (CRM)	72	84	69	73	50-80 cfu
pH	6.9	6.9	6.9	7.0	pH 7.0
DO (% sat)	84	116	95	108	100 %

Table # - Data set for calculating errors in task below. NOTE: cfu stands for colony forming units.

Task

Complete the following table of results by performing the calculations required.

Measurand	Average (reported value)	Absolute error	Relative error	Range	Absolute precision	Relative precision
Conductivity
Nitrate
E.Coli (CRM)
pH
DO (% sat)

Which measurand exhibits the best accuracy? How did you determine this?

Which measurand exhibits the best precision? How did you determine this?

Which measurand has the lowest range?