7th Grade Math

2 BEVERAGES You can use the recipe

shown to make a healthier version

of a popular beverage. Is the amount

of mix used proportional to the

amount of sugar used? Explain.

Find the amount of mix and sugar needed for different numbers of

batches and make a table to show these mix and sugar measures.

Cups of Sugar _^12    11 _^12    2

Envelopes of Mix 1234

Quarts of Water 2468

For each number of cups of sugar, write the relationship of the

cups and number of envelopes of mix as a ratio in simplest form.

cups of sugar

__envelopes of mix

_^12

_ 1 , _ 21 ,

1 _^12

_ 3 , _ 42

All of the ratios between the two quantities can be simplified to 0.5.

The amount of mix used is proportional to the amount of sugar used.

a. BEVERAGES In Example 2, is the amount of sugar used

proportional to the amount of water used?

b. MONEY At the beginning of the year, Isabel had $120 in the

bank. Each week, she deposits another $20. Is her account

balance proportional to the number of weeks of deposits?

(^) cup sugar
1 envelope of mix
2 quarts of water
Fruit Punch
21
For Exercises 1–4, explain your reasoning.
Examples 1 and 2 11 ELEPHANTS An adult elephant drinks about 225 liters of water each day.
Is the number of days that an elephant’s water supply lasts proportional
to the number of liters of water the elephant drinks?

2. PACKAGES A package shipping company charges $5.25 to deliver a
   package. In addition, they charge $0.45 for each pound over one pound.
   Is the cost to ship a package proportional to the weight of the package?


3. SCHOOL At a certain middle school, every homeroom teacher is assigned
   28 students. There are 3 teachers who do not have a homeroom. Is the
   number of students at this school proportional to the number of teachers?


4. JOBS Andrew earns $18 per hour for mowing lawns. Is the amount of
   money he earns proportional to the number of hours he spends mowing?

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Lesson 1C Proportions 273

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