Finding the Third Proportional to 256,878 and 395,320.50

Step by Step Solution

1. Step 1: Write the proportion equation
   256,878 : 395,320.50 = 395,320.50 : x
2. Step 2: Convert to fraction form
   256,878/395,320.50 = 395,320.50/x
3. Step 3: Cross multiply
   256,878x = 395,320.50 × 395,320.50
4. Step 4: Simplify right side
   256,878x = 156,278,297,720.25
5. Step 5: Solve for x
   x = 156,278,297,720.25/256,878
6. Step 6: Final answer
   x = 608,375.56