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Question
Find the fourth proportion to the following:
3,5 and 15
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Solution
Let x be the fourth proportion to 3,5 and 15
3 : 5 :: 15 : x
⇒ 3 × x = 5 × 15
⇒ x = `(5 xx 15)/3`
⇒ x = 25
The fourth proportion is 25.
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