GUIDE TO PROBLEM SOLVING Using Conversion Factors

Guide to Problem Solving Using Conversion Factors 

Write a plan to convert the given unit to the needed unit. 

In radiological imaging such as PET or CT scans, dosages of pharmaceuticals are based on body mass. If a person weighs 164 lb, what is the body mass in kilograms  

STEP0 Write a plan to convert the given unit to the needed unit. We see that the given unit is in the U.S. system of measurement and the needed unit in the metric system. Therefore, the conversion factor must relate the U.S. unit lb to the metric unit kg. 

Set up the problem to cancel units and calculate the answer. Write the given, 164 lb, and multiply by the conversion factor that has the unit lb in the denominator (bottcmi number) to cancel out the given unit (Ib) in the numerator. 

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