Answer:
The scale factor is

Explanation:
Given: Ratio of diameter of 2 circles which is y : z
To find: Scale Factor of the circles
Scale factor of circles is the ratio of their radii.
let, a is the same multiple which given exact value of diameter
⇒ The diameter of 1st circle = ya
⇒ Radius of 1st circle =

⇒ The diameter of 2nd circle = za
⇒ Radius of 2nd circle =

So, The scale factor =

=

=

=

Therefore, The scale factor is
