Question

find the fourth proportional to 1/3, 1/4 1/5

Answer 1

Answer:

given 1/3, 1/4, 1/5 are the three proportionals

let x be the fourth proportional

1/3, 1/4, 1/5, x are in proportion

1/3 : 1/4 = 1/5 : x

product of means = product of extremes

1/4 * 1/5 = 1/3 * x

1/20 = x/3

x = 3/20

fourth proportional = 3/20