Finding the Third Proportional to 258,418 and 548,142

Step by Step Solution

1. Step 1: Write the proportion equation
   258,418 : 548,142 = 548,142 : x
2. Step 2: Convert to fraction form
   258,418/548,142 = 548,142/x
3. Step 3: Cross multiply
   258,418x = 548,142 × 548,142
4. Step 4: Simplify right side
   258,418x = 300,459,652,164
5. Step 5: Solve for x
   x = 300,459,652,164/258,418
6. Step 6: Final answer
   x = 1,162,688.56