6th Grade Math Textbook, Progress

Write Proportions

11-6

Use the table above to write and solve a proportion to

find the number of gallons of gasoline for each trip.

1. Harold, 185 miles 2. Ann, 1050 miles 3. Paco, 3080 miles

Write a proportion. Then solve.

4. If apples sell at 3 for $.75, how many 5. If 12 calculators cost $60, what will
   apples can be bought for $4.25? 4 calculators cost?


5. If rent for 2 weeks is $750, how much 7. If 5 CDs cost $60, how much would
   rent is paid for 6 weeks? a dozen CDs cost?

At the given rate, how many gallons would

Meghan use on a 3600-mile trip?

To find the number of gallons, t, write and

solve a proportion.

When you write a proportion, be sure that the

two equivalent ratios compare similar things.


 Write two equal rates of miles to gallons.

 3600 miles

tgallons

30 miles

1 gallon

 Use the cross-products rule

to solve the proportion.

 30 t
 1  3600

30 t 30 
 3600  30

t
 120


 Check.

 
 30  120 
 1  3600 3600 
 3600

Meghan would use 120 gallons on a 3600-mile trip.

There are many ways to set up a proportion as long

as the equivalent ratios compare similar things.

 


1

t

30

3600

t

3600

1

30

3600

120

30

1

3600

t

30

1

3600

t

30

1

Average Miles Per Gallon

Meghan 30

Ann 35

Harold 37

Paco 38.5

miles per

gallon

total miles

in tgallons

gallons

miles

short trip

long trip

Think

Miles per gallon means

miles per 1 gallon.

Apply the Division Property of Equality.

??

1.3

8206-2_386-387 10/12/07 6:50 PM Page 386