Final answer:
To find what number 150.5 is 21.5% of, set up the equation 150.5 = (21.5/100) * x and solve for x, yielding the result that the number is 700.
Step-by-step explanation:
To solve the equation 150.5 is 21\(1\/2)\% of what number, we need to find the base number that 150.5 represents 21.5% of. Let's set up the equation where x is the number we are trying to find:
\(150.5 = \frac{21.5}{100} \cdot x\)
To solve for x, we divide both sides by the percentage in decimal form:
\(x = \frac{150.5}{0.215}\)
Using a calculator yields:
\(x = \frac{150.5}{0.215} = 700\)
Therefore, the number that 150.5 is 21\(1\/2)\% of is 700.