280 Essential Skills for Health Careers Success
Ratios
A ratio expresses the relationship between two numbers. Ratios can be used
to show how many times one number can be found within another number.
The quantities that are compared in a ratio are called the terms, or com-
ponents, of the ratio. The components are written with a colon (:) or the
word “to” between them. A ratio can also be expressed as a fraction.
Example: In Eastridge High School’s medical terminology class,
there are 15 girls and 10 boys. What is the ratio of girls to boys?
15:10 or 15 to 10 or 15/10
As was discussed with fractions, ratios can be reduced. Because both
15 and 10 can be divided by 5, you can use that number to reduce the ratio.
15 ÷ 5 = 3
10 ÷ 5 = 2
The ratio expressed in its lowest terms would be: 3:2 or 3 to 2 or 3/2
A ratio is written in the same order as the words describing it are writ-
ten. For instance, the newborn nursery in Eastridge Hospital has one nurse
for every four newborns, so the ratio of nurses to newborns would be
expressed as 1:4. But, if you wish to express how many newborns there are
in the nursery for every nurse, you would write the ratio 4:1.
If a ratio is known, you can determine what percentage one of the com-
ponents is of the whole. To do so, fi rst add the components together to
get the total. Then, divide the component for which you want to fi nd the
percentage by the total. Your answer will be a decimal fraction and you can
determine the percentage by multiplying the decimal by 100.
Example: In Eastridge Extended Care Hospital, the ratio of male
patients to female patients is 1:4. What is the percentage of male
patients at the hospital?
The ratio is 1:4, males to females.
The total number is 1 male + 4 females = 5.
The percentage of males in the hospital is 1/5 or 0.2
Multiply 0.2 by 100 to get the percentage. 0.2 × 100 = 20%
ratio
comparison of one quan-
tity with another, similar
quantity
Ratios in Real Life
1. Last month at Eastridge Hospital, 32 infants were born. Of these
32 deliveries, doctors performed 8 caesarean sections (surgical removal
of a baby). What is the ratio of caesarean sections to normal deliveries
expressed in lowest terms?
2. On his fl ight last week, Jamal sat next to a woman who was coughing
and sneezing throughout the entire trip. There were 8 people seated in
direct contact with the sick woman. Jamal and two other people became
sick a few days later. Of the people exposed to the germs, what was the
ratio of those who became sick to those who did not? What percentage
of people exposed became sick?
Real Life Scenario