Finding the Third Proportional to 257,853 and 398,443.50

Step by Step Solution

1. Step 1: Write the proportion equation
   257,853 : 398,443.50 = 398,443.50 : x
2. Step 2: Convert to fraction form
   257,853/398,443.50 = 398,443.50/x
3. Step 3: Cross multiply
   257,853x = 398,443.50 × 398,443.50
4. Step 4: Simplify right side
   257,853x = 158,757,222,692.25
5. Step 5: Solve for x
   x = 158,757,222,692.25/257,853
6. Step 6: Final answer
   x = 615,688.87