Finding the Third Proportional to 217,138 and 478,448

Step by Step Solution

1. Step 1: Write the proportion equation
   217,138 : 478,448 = 478,448 : x
2. Step 2: Convert to fraction form
   217,138/478,448 = 478,448/x
3. Step 3: Cross multiply
   217,138x = 478,448 × 478,448
4. Step 4: Simplify right side
   217,138x = 228,912,488,704
5. Step 5: Solve for x
   x = 228,912,488,704/217,138
6. Step 6: Final answer
   x = 1,054,225.83