To convert 1/2% to a ratio, we first convert it to a decimal by dividing by 100:
1/2% = 1/2 ÷ 100 = 0.005
Then we express this decimal as a ratio by putting it in the form of x:y:
0.005 = x:y
To simplify this ratio, we can multiply both sides by a factor that will make x and y whole numbers. For example, we can multiply both sides by 100:
0.005 × 100 = x:y × 100
0.5 = x:y
So 1/2% as a ratio is 1:200.