Four sizes of scaled text are shown.

what is the unknown scale size?
enter your answer as a decimal in the box. round only your final answer to the nearest thousandth.

Let
x> the unknown scale size

we know that

N 1> 2.618
N 2> x
N 3> 1
N 4> 0.618

to obtain the size N 4 > multiply the size N 3 by 0.618
so
to obtain  the size N 2 > multiply the size N 1 by 0.618
size N 2=2.618*0.618> 1.6179
x=1.618

the answer is
 the unknown scale size is 1.618