Find the fourth proportional to 9.6 kg, 7.2 kg, 28.8 kg

Sum

Let fourth proportional to 9.6 kg, 7.2 kg, 28.8 kg be x
then 9.6 : 7.2 : : 28.8 : x
⇒ 9.6 × x = 7.2 x 28.8
x = `(7.2 xx 28.8)/(9.6)`
= 21.6.

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Chapter 6: Ratio and Proportion - Exercise 7.2

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