Download 7.1 Ratios and Proportions A ratio is a comparison of two numbers

7.1 Ratios and Proportions
A ratio is a comparison of two numbers by division.
Ratios that make the same comparison are equivalent.
Example:
Make equivalent ratios by either multiplying or dividing
the numerator and denominator by the same number.
3
4
Find two ratios that are equivalent to 4
20
Ratios that are equivalent are said to be proportional,
or in proportion.
Two ways you can tell if two ratios form a proportion:
1. Simplify each ratio and see if they are equal fractions
3
27
and
2
18
2. If their cross products are equal, then the ratios
form a proportion.
3
27
?
=
2
18
A medicine for dogs indicates that the medicine should
be administered in the ratio 0.5 tsp per 5 pounds,
based on the weight of the dog.
Jaime has a 60 lb dog.
She plans to give the dog 12 teaspoons of medicine.
Is she administering the medicine correctly?
Jaime also has a 15 lb puppy.
She plans to give the puppy 1.5 tsp of medicine.
Is she administering the medicine correctly?
Sports statistics can be given as ratios.
Find the ratios for the given statistics.
In 69 games Darrel Armstrong of
the Orlando Magic had 136 steals
and 144 turnovers. What is his
steals per turnover ratio?
In 69 games, Ben Wallace
of the Detroit Pistons
blocked 234 shots. What is
his blocks per game ratio?