After the Cl-
determination in a bottle of water using IC and a calibration method I get:
X= 3,1786 mg/l
S calc. ("standard deviation") = 0,224780537 mg/l
Now I have to express the analitical data:
X ± t * S calc
3,1786 mg/l ± 0,484960449 mg/l
Have to approximate the uncertainty ""± 0,484960449 mg/l"" at the first non-zero term ??
Reading the J.R. Harrys usually the uncertainty is approximated at the first non zero term....
In this case I get: