Question

check whether the number 4,12,36 are in proportion

Answer 1

Let the fourth proportional to the numbers 4, 12, and 36be x.
4:12::36:c
4x = 12*36
x=108
Now, 4:12::36:108
4:12=4/12=1/3
36:108=36/108=1/3
12:36=12/36=1/3
Therefore 4 ,12,36 are in proportion