Finding the Third Proportional to 280,078 and 430,499

Step by Step Solution

1. Step 1: Write the proportion equation
   280,078 : 430,499 = 430,499 : x
2. Step 2: Convert to fraction form
   280,078/430,499 = 430,499/x
3. Step 3: Cross multiply
   280,078x = 430,499 × 430,499
4. Step 4: Simplify right side
   280,078x = 185,329,389,001
5. Step 5: Solve for x
   x = 185,329,389,001/280,078
6. Step 6: Final answer
   x = 661,706.34