Finding the Third Proportional to 331.59 and 520.17

Step by Step Solution

1. Step 1: Write the proportion equation
   331.59 : 520.17 = 520.17 : x
2. Step 2: Convert to fraction form
   331.59/520.17 = 520.17/x
3. Step 3: Cross multiply
   331.59x = 520.17 × 520.17
4. Step 4: Simplify right side
   331.59x = 270,578.78
5. Step 5: Solve for x
   x = 270,578.78/331.59
6. Step 6: Final answer
   x = 815.99