Finding the Third Proportional to 243,208 and 388,536

Step by Step Solution

1. Step 1: Write the proportion equation
   243,208 : 388,536 = 388,536 : x
2. Step 2: Convert to fraction form
   243,208/388,536 = 388,536/x
3. Step 3: Cross multiply
   243,208x = 388,536 × 388,536
4. Step 4: Simplify right side
   243,208x = 150,960,223,296
5. Step 5: Solve for x
   x = 150,960,223,296/243,208
6. Step 6: Final answer
   x = 620,704.18