Finding the Third Proportional to 256,402 and 398,044.50

Step by Step Solution

1. Step 1: Write the proportion equation
   256,402 : 398,044.50 = 398,044.50 : x
2. Step 2: Convert to fraction form
   256,402/398,044.50 = 398,044.50/x
3. Step 3: Cross multiply
   256,402x = 398,044.50 × 398,044.50
4. Step 4: Simplify right side
   256,402x = 158,439,423,980.25
5. Step 5: Solve for x
   x = 158,439,423,980.25/256,402
6. Step 6: Final answer
   x = 617,933.65