To find out what number 10.2 is 85% of, you can use the equation:
\[ 0.85 \times x = 10.2 \]
Where \( x \) is the number you are trying to find. To solve for \( x \), divide both sides of the equation by 0.85:
\[ x = \frac{10.2}{0.85} \]
Now, calculate \( x \):
\[ x = \frac{10.2}{0.85} \approx 12 \]
So, 10.2 is 85% of approximately 12.