The fourth proportional to the numbers 5, 6 and 8 is :

9.8 9.6 9 9.5

9.6

5 : 6 :: 8 : a ⇒ The fourth proportional a, ⇒ 5a = 6 x 8 ⇒ 5a = 48 ⇒ a = \(\frac{48}{5}\) = 9.6