Finding the Third Proportional to 270,553 and 428,390.50

Step by Step Solution

1. Step 1: Write the proportion equation
   270,553 : 428,390.50 = 428,390.50 : x
2. Step 2: Convert to fraction form
   270,553/428,390.50 = 428,390.50/x
3. Step 3: Cross multiply
   270,553x = 428,390.50 × 428,390.50
4. Step 4: Simplify right side
   270,553x = 183,518,420,490.25
5. Step 5: Solve for x
   x = 183,518,420,490.25/270,553
6. Step 6: Final answer
   x = 678,308.58