Finding the Third Proportional to 257,805 and 398,371.50

Step by Step Solution

1. Step 1: Write the proportion equation
   257,805 : 398,371.50 = 398,371.50 : x
2. Step 2: Convert to fraction form
   257,805/398,371.50 = 398,371.50/x
3. Step 3: Cross multiply
   257,805x = 398,371.50 × 398,371.50
4. Step 4: Simplify right side
   257,805x = 158,699,852,012.25
5. Step 5: Solve for x
   x = 158,699,852,012.25/257,805
6. Step 6: Final answer
   x = 615,580.97