Please help fast in solving this question.

Question

If y is the mean proportion of x and z , then the mean proportion of (x²+y²) and (y²+z²) is

Options:

1.xz+yz

2.xy-yx

3.xy+yz

4.yz-zx

Answer 1

Given that x/y = y/z, then x²/y² = y²/z² by squaring the given.

Now, making use of the Denominator Addition property* of a proportion, we conclude that 

(x²+y²)/y² = (y²+z²)/z².  Does this help?

 

*  this property is generally proved in every Geometry course...I hope it is something that you were taught.