Hello from MrBillDoesMath!
Answer:
3/16 is one answer
Discussion:
To be definite, let's find the average of 1/4 and 1/8. That number is rational and lies between the two values:
(1/4 + 1/8)/2 =
(2/8 + 1/8)/2 = (as 1/4 = 2/8)
( 3/8)/2 =
3/16
Thank you,
MrB