Finding the Third Proportional to 428.06 and 864.56

Step by Step Solution

1. Step 1: Write the proportion equation
   428.06 : 864.56 = 864.56 : x
2. Step 2: Convert to fraction form
   428.06/864.56 = 864.56/x
3. Step 3: Cross multiply
   428.06x = 864.56 × 864.56
4. Step 4: Simplify right side
   428.06x = 747,468.32
5. Step 5: Solve for x
   x = 747,468.32/428.06
6. Step 6: Final answer
   x = 1,746.17