RATIO & PROPORTION
Ratio and proportion is a way of calculating medication dosages.
A ratio is used to indicate a relationship between two numbers.
A proportion is an equation of two ratios of equal value.
A proportion can be written as follows:
1. Separated with an
=
sign
3 : 4
=
6 : 8
2. Written as a
fraction
3
=
6
4
8
Medication calculation problems will require you to solve for an unknown
quantity, which may be expressed as “x.”
Solve for X:
3
=
12
4
X
1.
Cross multiply.
3x
=
48
2.
Solve for x by dividing both sides
3x
=
48
by the coefficient of x (3)
3
3
3.
x = 16
You may check this problem by substituting the answer to X (16) back in the
problem.
3 X 16 = 48
4 X 12 = 48;
Therefore………..
48 = 48
ANSWER is CORRECT!
7