Rounding Results for Comparison with Specification - Pharmaceutical Technology

Latest Issue
PharmTech

Latest Issue
PharmTech Europe

 Pharmaceutical Technology All results
Rounding Results for Comparison with Specification
The mysteries of rounding are exposed.
 Apr 2, 2013 Pharmaceutical Technology Volume 37, Issue 4, pp. 122-124

Three rules for rounding The best explanation of unbiased rounding is in a 1947 textbook written by the statistical research group of Columbia University (2). The senior editor, Churchill Eisenhart from the (then) National Bureau of Standards, was one of the most influential statisticians of his era.

Here are the three rules: Rule 1: If the last digit to be dropped is less than 5, the last digit retained shall be left unchanged.

Rule 2: If the last digit to be dropped is greater than 5, or is 5 followed by digits greater than 0, the last digit retained shall be increased by 1.

Rule 3: If the last digit to be dropped is 5 alone or a 5 followed by 0 only, the last digit retained shall be rounded to the nearest even number.

 Figure 1: Decision tree for an unbiased rounding process.
It is usually easier to see how such a rule works if you draw it in a decision tree as shown in Figure 1. In this figure, we designate the digit or figure to be rounded by X, the digit or figure to be dropped by Y, and the difference between the truncated value and the full figure value by Z. Based upon the values of X, Y, and Z, we can arrive at the correct unbiased rounding decision.

| Weekly
| Monthly
|Monthly
| Weekly
 Survey
What role should the US government play in the current Ebola outbreak?
Finance development of drugs to treat/prevent disease.
Oversee medical treatment of patients in the US.
Provide treatment for patients globally.
All of the above.
No government involvement in patient treatment or drug development.
Finance development of drugs to treat/prevent disease. 23%
Oversee medical treatment of patients in the US. 14%
Provide treatment for patients globally. 7%
All of the above. 47%
No government involvement in patient treatment or drug development. 9%
Most Viewed Articles
 Columnists Outsourcing Outlook Jim MillerOutside Looking In sponsored by Ingredients Insider Cynthia ChallenerAdvances in Large-Scale Heterocyclic Synthesis Regulatory Watch Jill Wechsler New Era for Generic Drugs European Regulatory WatchSean MilmoTackling Drug Shortages