Step 1: Write the formula for determining what percent one number is of another:

\[ \text{x} = \left( \frac{a}{b} \right) \times 100 \]

where:

• \(a = 5\) (the part value)
• \(b = 28\) (the total value)

Step 2: Substitute the values into the formula:

\[ \text{x} = \left( \frac{ 5 }{ 28 } \right) \times 100 \]

Step 3: Simplify the fraction:

\[ \frac{ 5 }{ 28 } = 0.18 \]

Step 4: Multiply by 100 to convert to percentage:

\[ \text{x} = 0.18 \times 100 = 1.40 \]

Answer: 5% of 28 = 1.40