Applications of Proportions

EXAMPLE 6.40

Write each sentence as a proportion:

(a) $$3$$ is to $$7$$ as $$15$$ is to $$35$$.

(b) $$5$$ hits in $$8$$ at bats is the same as $$30$$ hits in $$48$$ at-bats.

(c) \(\$ 1.50\) for 6 ounces is equivalent to \(\$ 2.25\) for $$9$$ ounces.

EXAMPLE 6.41

Determine whether each equation is a proportion:

(a) \(\dfrac{4}{9}=\dfrac{12}{28}\)

(b) \(\dfrac{17.5}{37.5}=\dfrac{7}{15}\)

EXAMPLE 6.42

Solve: \(\dfrac{x}{63}=\dfrac{4}{7}\).

EXAMPLE 6.43

Solve: \(\dfrac{144}{a}=\dfrac{9}{4}\).

EXAMPLE 6.44

Solve: \(\dfrac{52}{91}=\dfrac{-4}{y}\).