Question

What number should be added to each of the number 12, 22,42 and 72 so that that resulting number may be in proportion

Answer 1

Answer:

3 should be added to each of the number 12, 22,42 and 72 so that that resulting number may be in proportion.

Step-by-step explanation:

Let

x should be added.

First number= 12 +x.

Second number =22 + x.

Third number = 42 + x.

Forth number = 72 + x.

( 12 + x ) : ( 22 + x )  ::  ( 42 + x ) : ( 72 + x )

Product of extremes = Product of means.

( 12 + x ) (72 + x ) = ( 42 + x ) ( 22 + x )

(12×72) + 12x + 72x + x ^2 = (42×22) + 42x + 22x + x ^2

864 + 84x + x ^2 =924 + 64x + x ^2

84x - 64x + x ^2- x ^2 = 924−864

20 x = 60

x = 60 / 20

x = 3.

3 should be added to each of the number 12, 22,42 and 72 so that that resulting number may be in proportion.