Question 97480
They are proportional if when you cross multiply they equal;
1. 50 over 40 equal 5 over 4
{{{50/40=5/4}}}
50*4=200
40*5=200  

2. 12 to 11, 36 to 33 
{{{12/11=36/33}}}
12*33=396
36*11=396 

3. 20:40, 1:2 
{{{20/40=1/2}}}
20*2=40
1*40=40 

4. 33 over 36 equals 44 over 48
{{{33/36=44/48}}}
33*48=1584
44*36=1584
They are all proportions
:)