Finding the Third Proportional to 172,821 and 359,436

Step by Step Solution

1. Step 1: Write the proportion equation
   172,821 : 359,436 = 359,436 : x
2. Step 2: Convert to fraction form
   172,821/359,436 = 359,436/x
3. Step 3: Cross multiply
   172,821x = 359,436 × 359,436
4. Step 4: Simplify right side
   172,821x = 129,194,238,096
5. Step 5: Solve for x
   x = 129,194,238,096/172,821
6. Step 6: Final answer
   x = 747,560.99