Finding the Third Proportional to 78,680 and 172,912

Step by Step Solution

1. Step 1: Write the proportion equation
   78,680 : 172,912 = 172,912 : x
2. Step 2: Convert to fraction form
   78,680/172,912 = 172,912/x
3. Step 3: Cross multiply
   78,680x = 172,912 × 172,912
4. Step 4: Simplify right side
   78,680x = 29,898,559,744
5. Step 5: Solve for x
   x = 29,898,559,744/78,680
6. Step 6: Final answer
   x = 380,002.03