Finding the Third Proportional to 512.72 and 666.28

Step by Step Solution

1. Step 1: Write the proportion equation
   512.72 : 666.28 = 666.28 : x
2. Step 2: Convert to fraction form
   512.72/666.28 = 666.28/x
3. Step 3: Cross multiply
   512.72x = 666.28 × 666.28
4. Step 4: Simplify right side
   512.72x = 443,930.70
5. Step 5: Solve for x
   x = 443,930.70/512.72
6. Step 6: Final answer
   x = 865.84