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.
- Harold, 185 miles 2. Ann, 1050 miles 3. Paco, 3080 miles
Write a proportion. Then solve.
- 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? - 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
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