Answer :

To express \(\frac{1}{2} \%\) as a decimal fraction, follow these steps:

1. Understand the Percentage:
\(\frac{1}{2} \%\) means half of a percent.

2. Convert the Fraction to a Decimal:
First, convert the fraction \(\frac{1}{2}\) to a decimal. The value of \(\frac{1}{2}\) is 0.5.

3. Convert Percentage to Decimal:
To convert a percentage to a decimal, divide by 100:
[tex]\[ \frac{1}{2} \% = 0.5 \times \frac{1}{100} = 0.5 \div 100 = 0.005 \][/tex]

Thus, \(\frac{1}{2} \%\) expressed as a decimal fraction is \(0.005\).

Therefore, the correct choice is:
(b) 0.005