Page 55 - Quality control of pharmaceuticals (07-PA 704)
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Example (4):
Comment on the accuracy and precision of the following data provided by two
analysts in the same laboratory using exactly the same method.
Exp No. Analyst 1 Analyst 2
1 99.7 99.8
2 98.9 101.7
3 99.1 102.8
4 100.1 100.2
5 99.9 98.9
6 99.1 101.0
Solution
1. Calculation of t calcu = 2.16
t-/theor = 2.228 (From t-table)
2. Calculation of variances S2
Fcalc = 1.958 /0.559 = 3.502
Ftheor = 5.05 (From F table)
Acceptance Limit: calculated t and F should be lower than the theoretical
Conclusion:
Since the t calc less than t theor: both analysts' mean results have the same
accuracy. Since the Fcalc less than F theor: both analysts have the same precision.
