Finding the Third Proportional to 258,042 and 398,569.50

Step by Step Solution

1. Step 1: Write the proportion equation
   258,042 : 398,569.50 = 398,569.50 : x
2. Step 2: Convert to fraction form
   258,042/398,569.50 = 398,569.50/x
3. Step 3: Cross multiply
   258,042x = 398,569.50 × 398,569.50
4. Step 4: Simplify right side
   258,042x = 158,857,646,330.25
5. Step 5: Solve for x
   x = 158,857,646,330.25/258,042
6. Step 6: Final answer
   x = 615,627.09