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Estimate the linearity of the measurement procedure.
The worksheet opens showing 3 columns. The Dilution column identifies the levels of the analyte in the sample (5 levels). Calcium identifies the measured value for 2 replicates of sample.
The analysis report opens.
The scatter plot shows a simple visual assessment of the linearity of the measurement
procedure over the measuring interval. The red line shows the linear fit, and the
green line shows the best non-linear (2nd or 3rd order polynomial) fit.
You should observe the scatter of the points to ensure there are no obvious problems.
No individual points stand out as atypical of the bulk of the data. The precision
table shows the precision to be constant across the measuring interval at an average
0.12mg/dL which is typical of that expected for the measurement procedure.
The linearity plot shows the difference between the linear and nonlinear fit across
the measuring interval. Five out of the six points are outside the criteria for
allowable nonlinear error.