If 2.5: x :: x : 4.9, and x>0, find the value of x

Correct option is D

Given:

2.5 : x :: x : 4.9

Formula Used:

If the numbers a,b,c and d are in proportions then:

a : b :: c : d

​$$a \times d = b \times c$$​​

Solution:

Hence the 2.5:x::x:4.9

​$$2.5 \times 4.9 = x \times x$$​​

​$$x^2 = 2.5 \times 4.9$$​​

​$$x= \sqrt{2.5 \times 4.9}$$​​

x = 3.5