Finding the Third Proportional to 129,978 and 284,780

Step by Step Solution

1. Step 1: Write the proportion equation
   129,978 : 284,780 = 284,780 : x
2. Step 2: Convert to fraction form
   129,978/284,780 = 284,780/x
3. Step 3: Cross multiply
   129,978x = 284,780 × 284,780
4. Step 4: Simplify right side
   129,978x = 81,099,648,400
5. Step 5: Solve for x
   x = 81,099,648,400/129,978
6. Step 6: Final answer
   x = 623,949.04