The proportion is .
Apply cross product property of equality: then
.
(Multiply:
)
(Apply distributive property:
)
(Multiply:
)
(Add 9 to each side)
(Apply additive inverse property:
)
(Apply additive identity property:
)
(Add:
)
Apply division property of equality: Divide each side by 3.
\ (Cancel common terms)
(Divide:
)
The value is .