Solving Proportions with Scale Factor

Which proportion would allow you to solve for the missing side, x?

• A

• B

• C

• D

Solve the proportion:

• c = 4

• c = 8

• c = 14

• c = 10

Solve for x 

• x = 6

• x = 25

• x = 28

• x = 17

Solve for x 

• x = 16

• x = 28

• x = 1/26

• x = 26

If the scale factor is 1 : 2.5, that means each side in figure B is 2.5 times as big as each side in figure A.

How long is side S?

Mathematical Equivalence

OFF

Fairview and Rockville are 104 miles from each other. How far apart would the cities be on a map that has a scale of 1 cm : 13 miles? Solve the proportion.

• 7 cm

• 1352 cm

• 8 cm

• 4 cm

Solve the proportion:

• 4

• 8

• 14

• 10

A map of a city uses a scale of 1 centimeter = 3.5 meters. If a road shown on the map runs for 25 centimeters, how long is the road?

• 0.14 meters

• 87.5 meters

• 7.14 meters

• 90 meters

When you solve proportions using the horizontal or ​ (a)   method, you are finding the scale ​ (b)  

If the ​ (c)   factor is bigger than 1, the digits get ​ (d)   .

The VALUE stays the SAME.

• vertical

• factor.

• scale

• bigger

Solve the proportion.

• k=5

• k=3.3333333

• k=60

• k=90