Finding the Third Proportional to 243,150 and 390,672

Step by Step Solution

1. Step 1: Write the proportion equation
   243,150 : 390,672 = 390,672 : x
2. Step 2: Convert to fraction form
   243,150/390,672 = 390,672/x
3. Step 3: Cross multiply
   243,150x = 390,672 × 390,672
4. Step 4: Simplify right side
   243,150x = 152,624,611,584
5. Step 5: Solve for x
   x = 152,624,611,584/243,150
6. Step 6: Final answer
   x = 627,697.35