Question

what must be added to number 1, 3, 10, 18 so that they are in proportion?​

Answer 1

Answer:

2 must be added to 1,3,10,18 so they become 3,5,12,20 and are in proportion. Pls mark me as brainliest.

Step-by-step explanation:

Let the number to be added be x

1+x : 3+x :: 10+x : 18+x

Product of means = product of extremes

(1+x)(18+x) = (3+x)(10+x)

$18 + x + 18x + x^2 = 30 + 3x + 10x + x^2\\19x + 18 = 13x + 30\\19x - 13x = 30 -18\\6x = 12\\x = 2$

Answer 2

Answer:

2 is the answer

Step-by-step explanation:

hope it helps