Math and Dosage Calculations for Health Care 3rd Edition by James Whaley, Kathryn Booth, Booth Kathryn

Exercise 111

The flow rate in mL/hr can be found by forming the dimensional
analysis (DA) equation using the dimensions of all the quantities
involved in the calculation. The dimensions are arranged to give
the desired dimensions on cancellation of the common dimensions.
The following DA equation must be used to find the flow rate in
mL/hr. The first factor is the micrograms of ordered dose, the second
is evidently the body weight, the third is the reciprocal of the
concentration of the available drug, and the last three are the
conversion factors from minute to hour, micrograms to milligrams,
and pounds to kilograms.