Finding the Third Proportional to 243,918 and 388,462.50

Step by Step Solution

1. Step 1: Write the proportion equation
   243,918 : 388,462.50 = 388,462.50 : x
2. Step 2: Convert to fraction form
   243,918/388,462.50 = 388,462.50/x
3. Step 3: Cross multiply
   243,918x = 388,462.50 × 388,462.50
4. Step 4: Simplify right side
   243,918x = 150,903,113,906.25
5. Step 5: Solve for x
   x = 150,903,113,906.25/243,918
6. Step 6: Final answer
   x = 618,663.30