What should be added to 315 38 and 134 so that the number become proportional to each other?

What number must be added to each of the numbers 15, 17, 34 and 38 to make them proportional?

Let x be added to each number, then numbers will be15 + x, 17 + x, 34 + x, and 38 + x.Now according to the condition`(15 + x)/(17 + x) = (34 + x)/(38 + x)`⇒ (15 – x)(38 + x) = (34 + x)(17 + x)

⇒ 570 + 53x + x2 = 578 + 51x + x2

∴ 4 is to be added.

Concept: Concept of Proportion

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