Finding the Third Proportional to 322.72 and 512.86

Step by Step Solution

1. Step 1: Write the proportion equation
   322.72 : 512.86 = 512.86 : x
2. Step 2: Convert to fraction form
   322.72/512.86 = 512.86/x
3. Step 3: Cross multiply
   322.72x = 512.86 × 512.86
4. Step 4: Simplify right side
   322.72x = 263,024.74
5. Step 5: Solve for x
   x = 263,024.74/322.72
6. Step 6: Final answer
   x = 815.03