Finding the Third Proportional to 380,755.50 and 505,419

Step by Step Solution

1. Step 1: Write the proportion equation
   380,755.50 : 505,419 = 505,419 : x
2. Step 2: Convert to fraction form
   380,755.50/505,419 = 505,419/x
3. Step 3: Cross multiply
   380,755.50x = 505,419 × 505,419
4. Step 4: Simplify right side
   380,755.50x = 255,448,365,561
5. Step 5: Solve for x
   x = 255,448,365,561/380,755.50
6. Step 6: Final answer
   x = 670,898.69