Finding the Third Proportional to 280,384 and 428,760

Step by Step Solution

1. Step 1: Write the proportion equation
   280,384 : 428,760 = 428,760 : x
2. Step 2: Convert to fraction form
   280,384/428,760 = 428,760/x
3. Step 3: Cross multiply
   280,384x = 428,760 × 428,760
4. Step 4: Simplify right side
   280,384x = 183,835,137,600
5. Step 5: Solve for x
   x = 183,835,137,600/280,384
6. Step 6: Final answer
   x = 655,654.88