Find the fourth proportional to 3, 12, 15

Sum

Let fourth proportional to
3, 12, 15 be x.
then 3 : 12 :: 15 : x
⇒ 3 × x = 12 x 15
x = `(12 xx 15)/(3)`
= 60.

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Chapter 6: Ratio and Proportion - Exercise 7.2

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