Question

900 is 4 1/2% of what?

Answer 1

Simple, first change the 4.5% into 0.045

Thus,

900=0.045*n

900/0.045=0.045n/0.045

20,000=n

Thus, your answer is 20,000.

Answer 2

900 = 4 1/2 % of what?

Let the what be  x,    4 1/2% = 9/2% =  (9/2)/100 = 9/200

900 = (9/200)*x

900 = 9x/200

9x = 900*200

x = (900*200)/9 = 20000

Therefore 900 is 4 1/2% of 20000