7th Grade Math

= Step-by-Step Solutions begin on page R1.

Extra Practice begins on page EP2.

Solve each proportion.

6. 7 k = 5632 7. 13 x = ^1839 8. ^44 p = ^115 9. _w^2 = _0.40.7


7. 256 = 30 d 11. _2.5 6 = _h 9 12. _3.5 8 = 3.2a 13. ^489 = _^72 n

Assume the situations are proportional. Write and solve a proportion.

14. COOKING Evarado paid $1.12 for a dozen eggs. Determine the cost of
    3 eggs.


15. TRAVEL A certain vehicle can travel 483 miles on 14 gallons of gasoline.
    Determine how many gallons of gasoline this vehicle will need to travel
    600 miles. Round to the nearest tenth.


16. ILLNESS For every person who actually has the flu, there are 6 people
    who have flu-like symptoms resulting from a cold. If a doctor sees
    40 patients, determine how many of these you would expect to have
    a cold.


17. LIFE SCIENCE For every left-handed person, there are about 4 right-handed
    people. If there are 30 students in a class, predict the number of students
    who are right-handed.


18. TRAVEL A speed limit of 100 kilometers per hour (kph) is approximately
    equal to 62 miles per hour (mph). Predict the following measures. Round
    your answers to the nearest whole number.
    a. a speed limit in mph for a speed limit of 75 kph
    b. a speed limit in kph for a speed limit of 20 mph
    Example 3 1919 MEASUREMENT The width of a woman’s shoulders is proportional to her
    height. A woman who is 64 inches tall has a shoulder width of 16.2 inches.
    Find the height of a woman who has a shoulder width of 18.5 inches.


19. COOKING A recipe calls for 1 _^12 tablespoons of cinnamon for every
    3 tablespoons of sugar. If you want to increase the recipe and use
    6 tablespoons of sugar, how many tablespoons of cinnamon would
    you need? Explain your reasoning.


20. PLANETS Use the table to write a proportion Weights on Different Planets
    Earth Weight = 120 pounds
    Mercury 45.6 pounds
    Venus 109.2 pounds
    Uranus 96 pounds
    Jupiter 304.8 pounds

relating the weights on two planets. Then

find the missing weight. Round to the

nearest tenth.

a. Earth: 90 pounds; Venus: pounds

b. Mercury: 55 pounds; Earth: pounds

c. Jupiter: 350 pounds; Uranus: pounds

d. Venus: 115 pounds; Mercury: pounds

22. MATH IN THE MEDIA Find an example of a ratio in a newspaper, on
    television, or on the Internet. Write an equivalent ratio. Then use a
    proportion to verify that the ratios are equivalent.

Example 1

Example 2

64 in.

16.2 in.

Real-World Link

Although people vary

in size and shape, in

general, people do

not vary in proportion.

RRR

A

C

Lesson 1D Proportions 279

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