2.4 Ratio and Proportion
Day 2
Objective: SWBAT compute unit rates and
to solve proportions.
Mini Quiz 17
1. Solve 8(x + 3) = 7(4)
2. Solve 0.3(x – 4) = 0.3x – 1.2
1

3. Solve 4  x   5
4

Quick Review
1. Express in miles per hour: 1 mi in 3 min
20 mi/hr
2. Fresh Flowers sells six roses for $7.50. Find
the unit rate.
$1.25/rose
3. In converting rates, how do you set it up?
What you
What you
Know
Want
Proportion
equation that states two
Proportion: an ________
ratios are equal,
______
a c for b ≠ 0 and d ≠ 0

b d
(aka a:b = c:d)
Solving Proportions
t 5
1. Solve 18 •  • 18
9 6
2t = 15
15
t=
2
LCD: 18
Solving Proportions
2. Solve
x 25

4 12
LCD:
25/3
Solving Proportions
x4 x2
3. Solve

5
7
LCD:
-19
Solving Proportions
4. Solve
x2 x

14
10
LCD:
5
Solving Proportions
3
5
5. Solve

w6 w4
LCD:
-21
Solving Proportions
8
4
6. Solve

b  10 2b  7
LCD:
8
Using Proportions for Word
Problems
7. A canary’s heart beats 200 times in 12
seconds. Use a proportion to find how many
times its heart beats in 42 seconds.
700 beats
Using Proportions for Word
Problems
8. A box of cereal weighing 350 grams contains
21 grams of fat. Find the number of grams
of fat in the recommended serving size of 50
grams.
3 grams
Wrap Up
 Proportion – 2 ratios that =

Fractions  Find LCD
HW: P. 96 #17-23 odd, 24, 27-45 odd
Write your DLUQ.