Ratios and Proportions Set Up

A ratio is

• comparing a bunch of numbers

• a comparison between 2 quantities

• an estimation of an amount

• a variable

A proportion is a

• ratio statement

• an "if-then" statement

• a statement of 2 ratios

• a comparison

All of the following are proper representations of a ratio EXCEPT

• a/b

• a to b

• a:b

• a over b

To solve for missing info in a proportion statement you must first

• Cross multiply

• Divide everything

• Get rid of variables

• Guess

An engineer created a scale drawing of a building using a scale in which 0.25 inch represents 2 feet. The length of the actual building is 250 feet. What is the length in inches of the building in the scale drawing? Set up the proportion box based on the given labels.

e

f

g

d

x

0.25

2

25

100

20

250

1.75

Is the pair of ratios proportional?

• yes

• no

Are the two ratios proportional?

• YES

• NO

A recipe for fruit salad includes 1/3 cup of grapes for 4 servings. How many cups of grapes are needed for 30 servings of this fruit salad?

Set up the proportion box based on the given labels.

d

e

f

g

30

100

1/3

34

x

4

26

An engineer created a scale drawing of a building using a scale in which 0.25 inch represents 2 feet. The length of the actual building is 250 feet.

 

What is the length in inches of the building in the scale drawing?

Set up the proportion box based on the given labels.

e

f

g

d

x

2

20

250

1.75

0.25

100

25

Set up this proportion: Vito uses 9 liters of water to water 24 flower pots. He is wondering how many liters of water (w), it would take to water 40 flower pots. He assumes he'll use the same amount of water on each pot.