Finding the Third Proportional to 255,089.25 and 398,142

Step by Step Solution

1. Step 1: Write the proportion equation
   255,089.25 : 398,142 = 398,142 : x
2. Step 2: Convert to fraction form
   255,089.25/398,142 = 398,142/x
3. Step 3: Cross multiply
   255,089.25x = 398,142 × 398,142
4. Step 4: Simplify right side
   255,089.25x = 158,517,052,164
5. Step 5: Solve for x
   x = 158,517,052,164/255,089.25
6. Step 6: Final answer
   x = 621,418.00