Finding the Third Proportional to 78,397 and 172,401

Step by Step Solution

1. Step 1: Write the proportion equation
   78,397 : 172,401 = 172,401 : x
2. Step 2: Convert to fraction form
   78,397/172,401 = 172,401/x
3. Step 3: Cross multiply
   78,397x = 172,401 × 172,401
4. Step 4: Simplify right side
   78,397x = 29,722,104,801
5. Step 5: Solve for x
   x = 29,722,104,801/78,397
6. Step 6: Final answer
   x = 379,122.99