Finding the Third Proportional to 78,404 and 172,415

Step by Step Solution

1. Step 1: Write the proportion equation
   78,404 : 172,415 = 172,415 : x
2. Step 2: Convert to fraction form
   78,404/172,415 = 172,415/x
3. Step 3: Cross multiply
   78,404x = 172,415 × 172,415
4. Step 4: Simplify right side
   78,404x = 29,726,932,225
5. Step 5: Solve for x
   x = 29,726,932,225/78,404
6. Step 6: Final answer
   x = 379,150.71