The ratio canbe written in
the following form:
⁄ (fraction form),
𝑥 𝑦
x:y(read as “x is to y”),x to
y
4.
The word toseparates the numerator and
denominator quantities.
The ratio of 12 to 17 translates to
12
17
.
Numerator Denominator
Unit ratio: A ratio with a denominator of 1.
5.
Solve the followingproblems.
1. Matt and Andrew obtained 36
and 45 points, respectively , in
their math quiz. Express the
scores of Matt and Adrew as a
ratio.
6.
2. The measuresof the two
consecutive angles of a
parallelogram are in ratio of 5:7.
Find their measure.
7.
3. An angle40° more that
its supplement. Find the
ratio of the angle to its
supplement.
Proportions
4
3
8
6
Proportion: two ratiosset equal.
24
6
4
24
8
3
Cross-products of proportions are always equal!
Only works if there is an equal (=) sign!
4
3
8
6
No!
16.
REVIEW:Supply the missingnumbers or
variables which will make the statement
proportionality.
1. 3
4
=
12
Solving Proportions
x
18
20
12
x
x 12
12
360
18
20
360
12
x
12
12
30
x
1. Calculate the cross products.
2. Set the cross products equal.
3. Solve the equation.
x
18
20
12
2.
22.
Solving Proportions
3
7
6
5
x
5
3
x 42
42
5
3
x
9
x
1. Calculate the cross products.
2. Set the cross products equal.
3. Solve the equation.
42
15
3
x
27
3
x
3
3
3.
23.
Find the valueof the indicated
variables in each proportion.
1. 10: 5 = k: 4 3. =
2. = 4.
Set up aproportion to solve each
problem.
1. The ratio of boys to girls is 3 to 2. If
there are 12 boys, how many girls are
there?
2. It takes one Super Giant Pizza to feed
3 people. If you invite 36 people, how
many pizzas will you need?
28.
3. If twopounds of meat will serve 8
people, how many pounds will be
needed to serve 16 people?
29.
3. If twopounds of meat will serve 8
people, how many pounds will be
needed to serve 16 people?
4.If a jogger runs 2 miles and burns
186 calories, how many calories
would he burn jogging 3 miles?
30.
Jack was plantinga tree. He was
to dig a hole that was 3 feet
deep for every 8 feet of tree
height. How deep should he dig
the hole for a tree that is 24
feet high?
31.
A person whoweighs 200 pounds on
Earth would weigh about 32 pounds
on the moon. Find the weight of a
person on Earth who would weigh 52
pounds of the moon.
32.
Because of slumpingsales, a small
company had to lay off some of its
employees. The ratio of total
employees to employees laid off is 5
to 1. Find the total number of
employees if 22 are laid off.
