Question

Find the value of x in each of the following proportions:
(i) 55 : 11 : : x : 6
(ii) 27 : x : : 63 : 84
(iii) 51 : 85 : : 57 : x
(iv) x : 92 : : 87 : 116

Answer 1

(i) 55:11::x:6
Product of extremes = Product of means
55 × 6 = 11 × x
⇒ 11x = 330
⇒ x = 330 = 30
11
(ii) 27:x::63:84
Product of extremes = Product of means
27 ​× 84 = x ​× 63
⇒ 63x = 2268
⇒ x = 2268 = 36
63
(iii) 51:85::57:x
Product of extremes = Product of means
51 × x = 85 × 57
⇒ 51x = 4845
⇒ x = 4845 = 95
51
(iv) x:92::87:116
Product of extremes = Product of means
x × 116 = 92 ​× 87
⇒ 116x = 8004
⇒ x = 8004 = 69
116