What is the ratio of the fourth proportional of 2, 5, 6 to the fourth proportional of 6, 8, 9?
Show answer & explanation
Correct answer: D
Explanation
The correct answer is Option 4 i.e. 5 : 4.
Formula used:
The fourth proportion of a, b, c and x
⇒ x = bc/a ----- (1)
Calculations:
Let the fourth proportional of 2, 5, 6 be m.
⇒ m = 5 × 6/2 = 15
Let the fourth proportional of 6, 8 and 9 be n
⇒ n = 8 × 9/6 = 12
Required ratio = m : n = 15 : 12 = 5 : 4