Answer:
Unknown scale size is 1.25
Explanation:
There are four sizes are of scaled text shown in the picture.
Scaled text text means 3rd text is multiplied with a common factor to give the 4th text.
Finally we can say that we are getting these images scaled in a geometric sequence.
Now we have to get the second term of this sequence.
1, ?, 1.563, 1.954
Since explicit formula of a geometric sequence is

Here a = first term of the sequence
r = common ratio
n = number of term
Now common ratio = r = 4th term/third term = 1.954/1.563 = 1.25
Now 2nd term =

Therefore unknown scale size is 1.25