Finding the Third Proportional to 212.50 and 320.31

Step by Step Solution

1. Step 1: Write the proportion equation
   212.50 : 320.31 = 320.31 : x
2. Step 2: Convert to fraction form
   212.50/320.31 = 320.31/x
3. Step 3: Cross multiply
   212.50x = 320.31 × 320.31
4. Step 4: Simplify right side
   212.50x = 102,600.10
5. Step 5: Solve for x
   x = 102,600.10/212.50
6. Step 6: Final answer
   x = 482.82