Finding the Third Proportional to 78,800 and 172,909

Step by Step Solution

1. Step 1: Write the proportion equation
   78,800 : 172,909 = 172,909 : x
2. Step 2: Convert to fraction form
   78,800/172,909 = 172,909/x
3. Step 3: Cross multiply
   78,800x = 172,909 × 172,909
4. Step 4: Simplify right side
   78,800x = 29,897,522,281
5. Step 5: Solve for x
   x = 29,897,522,281/78,800
6. Step 6: Final answer
   x = 379,410.18